If you only email people occasionally — or once a year — this one is specifically for you!
I had a call recently with a potential client that summed up one of the most common deliverability challenges I come across — and one of the least discussed.
Their situation: customers sign up, they receive something of value, and then the business might need to contact them again — but not for months, sometimes years. A product bought annually. A service with a long gap between purchase cycles. A seasonal business that activates once or twice a year. And their question was a smart one: if deliverability is built on engagement, what happens to it when we are not emailing anyone?
This is a genuinely difficult problem. Most deliverability advice is written for teams who send at least weekly. The guidance for people who send quarterly, seasonally, or only when they have something specific to say is thin — and a lot of what does exist is wrong.
So this blog is specifically for infrequent and seasonal senders. It explains how deliverability works in this context, why stopping and starting is a problem, what actually happens to your sender reputation over time, and — most importantly — what you can do about it so that when you do need to email your list, your emails actually arrive.
If you want to go deeper on deliverability overall, I cover everything — auditing, monitoring, recovering, and the full technical picture — in my deliverability programme. This blog gives you the foundation for your specific situation. The programme gives you the certification and the complete toolkit.
Before we get into the infrequent sender problem, it is worth being precise about what we mean by deliverability — because it gets misused constantly.
Deliverability is not the same as delivery.
Delivery is whether the receiving server accepted your email. Your ESP will report this as your delivery rate — 97%, 98%, 99%. This looks reassuring but it tells you almost nothing useful. It means the server said yes. It does not mean anyone saw the email.
Deliverability is about placement. Where did the email land once it was accepted? In the inbox? The promotions tab? Spam? Nowhere visible at all?
Good deliverability means the majority of your emails land in the inbox or promotions folder — not in spam, not being silently filtered. Some of your emails will go to spam regardless. If you send to 7,000 people, a small number of those will end up in spam folders — that is normal. Good deliverability is not a guarantee of zero spam placement. It is a consistent pattern of inbox placement for the majority of your sends.
Deliverability is made up of two main things:
Technical authentication — SPF, DKIM, DMARC. Get it right and it works in the background. Most ESPs walk you through this setup. It is important but it is not usually where infrequent senders have their problems.
Sender reputation — this is the one that matters enormously for infrequent and seasonal senders. It is what the rest of this blog is about.
Every inbox provider — Gmail, Microsoft, Yahoo — maintains their own view of how trustworthy you are as a sender. This is your sender reputation. It is not a universal score. Gmail builds its own model. Microsoft builds its own. They do not share data. Your reputation can be different at each provider simultaneously.
What they are all assessing is the same thing: does this sender's audience want these emails?
They assess this through signals and events.
A signal is a behavioural indicator that accumulates over time.
Positive signals:
Opens — someone opened your email (with all the reliability caveats that come with that)
Clicks — a stronger signal of genuine engagement
Replies — one of the strongest positive signals available, tells providers this is a real conversation
Moving from spam to inbox — a recipient retrieving your email from spam actively tells the provider they want it
Filing to a folder — signals value and intentional engagement
Negative signals:
Spam complaints — the single most damaging signal. A direct instruction from the recipient to the provider.
Delete without opening — consistent, repeated deletion is a pattern providers learn from over time
Sustained non-engagement — a pattern that builds slowly and tells providers this audience has stopped caring
An event is something that happens at scale and causes a sudden shift in how providers view you, rather than the gradual influence of signals.
Negative events:
Bounce spikes — a large number of hard bounces in a single send tells providers you have not maintained your list, you are potentially sending to people who should not be there, or your data has gone stale. This is one of the fastest ways to damage sender reputation significantly.
Spam complaint spikes — going above threshold in a short window triggers an immediate reputation impact. Google's guidance: above 0.10% warrants attention, above 0.30% causes serious inbox placement problems.
Sudden volume increases — sending to 70,000 people when you normally send to 5,000 is a recognised red flag. Spammers build lists and blast them. Providers recognise this pattern immediately.
Positive events:
A high-engagement send — strong engagement from a meaningful number of recipients boosts reputation directly
Sustained consistency — a regular pattern of sending with stable positive signals over time is one of the most powerful reputation-building behaviours available
Here is the core problem for infrequent senders, stated plainly.
Sender reputation decays when you go quiet.
Inbox providers build their models on patterns. If you send consistently — even infrequently but on a recognisable schedule — they know what to expect from you. If you send and then disappear for six months and then send again, that pattern looks irregular. And irregular patterns are associated with spammers, compromised accounts, and bad actors who acquire lists and blast them sporadically.
This does not mean your emails will automatically go to spam after a period of inactivity. What it means is that when you do send again, you are starting from a weaker position than a sender who has been maintaining consistent engagement throughout. And if your returning send also has list health problems — stale data, old addresses that have become spam traps — you compound the problem significantly.
Let's make this concrete.
Subscriber A signs up to your list. Over the following months they receive emails but ignore all of them. They delete without opening, consistently. Gmail notices this pattern. Over time it starts routing your emails to spam for this subscriber — because their behaviour tells Gmail they do not want what you're sending.
Subscriber B signs up at the same time. They engage with the first few emails. They click something once. They occasionally open. Even if Subscriber B later goes quieter, the earlier engagement means Gmail has a positive reference point. Your emails continue landing in the inbox for this subscriber.
Now you run a seasonal campaign six months later. For Subscriber A, your emails are already going to spam — the campaign does not reach them. For Subscriber B, you have a real chance of inbox placement because you protected that relationship through their earlier engagement.
The lesson: the quality of engagement at the start of the relationship matters enormously for what happens to deliverability later. Which means your entry-point strategy — how people come onto your list and what happens in the first emails they receive — is not just about retention. It is deliverability infrastructure.
If you go completely quiet — no sends at all for an extended period:
Your domain's sending history becomes less recent and therefore less well-established in provider models
Your list ages. Addresses that were valid six months ago may have become abandoned, changed jobs, or — in the worst case — spam traps
When you return and send, you look like an irregular sender to some providers, which means your emails get evaluated more cautiously
Any bounce rate issues from the aged list create a negative event on your first send back — the worst possible moment to have one
The good news is that this is a solvable problem. It requires thinking differently about what your email programme does during the periods when you have nothing specific to sell or communicate — but it is entirely manageable.
There are two things you need to do simultaneously: maintain sender reputation in the background, and keep something warm coming into your list throughout the year.
The most powerful thing an infrequent sender can do for their deliverability is maintain a steady flow of intentional opt-ins throughout the year.
When someone opts into your list intentionally — because they genuinely want something you offer — the first emails they receive generate strong positive signals. They go into their inbox to retrieve what they signed up for. They open. They click. They engage. Those early positive signals feed your sender reputation and keep it healthy even during periods when your broader list is sitting quiet.
This is the inbox-first strategy. When someone signs up for something — a lead magnet, a guide, a resource, a quiz result — you do not deliver it on the page. You send it to their inbox. They have to go and get it. That is a deliberate, intentional inbox visit that fires positive engagement signals at the exact moment those signals are most valuable.
I have never worked with a business — in any sector, of any size, whatever the product — where we could not find something worth putting behind an inbox-first opt-in. Not something promotional. Something genuinely useful to the audience that makes the inbox visit feel worth it. A checklist. A guide. A template. A quiz result. Something that earns the relationship rather than just collecting an email address.
The volume does not need to be huge. A steady trickle of 20, 50, 100 warm new subscribers a month — people who are actively engaging with your first emails — does more for your sender reputation than 5,000 cold contacts sitting idle. Because those warm people are generating the positive signals that tell inbox providers you are a trusted, wanted sender.
The second tool available to infrequent and seasonal senders is inbox warming platforms.
These tools simulate positive sending behaviour for your domain. They send emails between seed accounts and automatically open them, click them, and move them from spam to inbox — generating the positive signals that build sender reputation in the background, without you having to send to your actual audience.
Warming platforms are not a replacement for genuine list engagement. They are a supplement — something you run in the background during the periods when your actual sends are low or absent.
For clients who have seasonal peaks — particularly around Black Friday or other major commercial moments — this is something I build into the plan at least six months before the peak. You do not start warming two weeks before your biggest send of the year. You build reputation steadily throughout the preceding months so that when you need it, it is already there.
A warming plan for a seasonal sender typically looks like:
Run a warming platform consistently from the beginning of the year, or at least from six months before peak
Combine with an inbox-first opt-in strategy that brings in warm new subscribers throughout the year
Gradually ramp actual send volume in the six to eight weeks before your peak, not overnight
Monitor reputation signals throughout the ramp — complaint rates, bounce rates, open rate patterns
Go into the peak with a domain that has been consistently active, not one that has been dormant for months
This is where the most creative thinking is required — and also where the biggest long-term value sits.
For infrequent senders, the instinct is often to only email when you have something to sell. I understand that instinct. You do not want to email for the sake of it. You do not want to create noise.
But there is a meaningful difference between emailing for the sake of it and emailing with genuine value that does not lead directly to a sale. The former damages your relationship with subscribers and your sender reputation. The latter builds both.
The question to ask is not what can we sell right now — because if it is the quiet season, the answer is nothing, and you should not email. The question is: what would be genuinely useful or interesting to this audience right now, that is relevant to what we do, but does not require them to buy anything?
This is where audience understanding becomes the entire ballgame. The right answer is completely different for different businesses:
A seasonal food brand might share recipes, seasonal guides, or behind-the-scenes content in the off-season
A B2B software company might share industry insights, trend reports, or research findings that help their audience do their jobs better
A holiday lettings business might send destination content, travel planning guides, or local area updates during the booking gap
A professional services firm might send regulatory updates, thought leadership, or practical guides relevant to their clients' world
An events business might share content from past events, speaker highlights, or sector commentary between seasons
Even once a month, if the content is genuinely valuable and relevant to the people receiving it — that is enough to maintain a consistent sending pattern and generate enough positive signals to protect your sender reputation through the quiet periods.
The key constraints:
It must be relevant to your brand and your audience — content that comes from nowhere creates confusion and negative signals
It must not be promotional if you have nothing to sell right now
It must be consistent — same sender name, same recognisable pattern. Consistency is what providers learn from. Inconsistency looks suspicious.
It must genuinely earn the relationship — if you received this email, would you be glad it arrived? If the answer is no, do not send it.
There is one more dimension of the infrequent sender challenge that needs addressing: what happens to your contact list during the quiet periods.
Email addresses are not static. They change, expire, and degrade over time.
Job changes in B2B — professional email addresses become invalid when people change roles. Some organisations keep old mailboxes live for a period, but eventually those addresses stop working or become unmonitored
Abandoned personal inboxes — people change providers, create new addresses, stop checking old ones. An address that was active when someone signed up could be functionally dead a year later
Spam traps — some abandoned addresses are repurposed by inbox providers as spam traps. Sending to a spam trap is a damaging event for sender reputation. The longer your list sits without being emailed, the greater the risk that some addresses have moved into this category
Changed circumstances — the person who signed up for your list last spring may have completely different needs, interests, or professional situations now
What this means practically: the longer the gap between your sends, the more list hygiene work you need to do before your next significant send. Going straight from six months of silence to a big campaign is one of the most reliable ways to generate a bounce spike — exactly the negative event you most need to avoid.
If you have had a period of low or zero sending and are approaching a moment where you need to send at scale:
Run your list through an email validation tool first. Services like ZeroBounce or NeverBounce flag invalid addresses, high-risk addresses, and known spam traps before you send to them. Remove the flagged addresses before you do anything else.
Segment by last known engagement. If you have engagement data — even old data — segment your list by last interaction. Your most recently engaged contacts are your safest group to send to first.
Ramp gradually. Do not go from zero to full list on day one. Send to your smallest, most engaged segment first. Monitor bounce rate, complaint rate, and open patterns before expanding.
Start with your cleanest, most intentional opt-ins. People who signed up because they genuinely wanted to hear from you are your most valuable asset when rebuilding momentum. They are most likely to generate positive signals.
Have a re-permission email ready. For contacts who have been completely silent for an extended period, a genuine re-permission email before your main campaign can protect your sender reputation by removing people who have truly moved on.
This is the most important thing I want you to take from this blog.
Most infrequent and seasonal senders think about deliverability the way they think about last-minute packing for a flight — something to deal with urgently when you need it. They want good inbox placement in November. So they start thinking about deliverability in October.
That is not how sender reputation works. You cannot build in four weeks something that should have been built over twelve months. You can do damage control, and if your foundations are reasonable you can ramp up carefully and probably be okay. But you will always be starting from a weaker position than you need to be in, at exactly the moment when inbox placement matters most.
The infrequent senders who consistently land in the inbox when it counts are the ones who treat deliverability as infrastructure — something maintained all year, not something fixed before each seasonal push.
That means:
Something coming into the list throughout the year through intentional opt-ins
Something going out throughout the year — even infrequently — that is genuinely valuable and consistent
Reputation maintained in the background through warming tools during the quietest periods
List health checked regularly, not just before a big send
A warm-up plan that starts months before any significant volume increase
None of this is complicated. All of it requires treating email as a channel that needs ongoing attention rather than periodic activation.
The businesses that get this right consistently outperform the ones that do not — not because they have better products or better copy, but because when they send, their emails actually arrive.
If this blog has made you realise your deliverability for upcoming sends is less protected than you'd like, here is a practical starting point:
Define your seasonal peak. When do you most need inbox placement? Work backwards from that date — six months is ideal for building a proper warm-up plan.
Audit your current list health. When did you last clean your list? When did you last send? What does your bounce rate history look like? Understand what you are working with before you do anything else.
Find your inbox-first opt-in. What can you give people that is genuinely valuable — that they would happily go into their inbox to retrieve? That is your deliverability foundation for the year.
Look at your off-season content. What can you say to your audience during the quiet periods that is relevant, valuable, and consistent? Even once a month is enough to maintain a sending pattern.
Consider a warming platform. If you have extended periods of silence, look at whether domain warming makes sense as background infrastructure for your programme.
Get certified. If you want to understand deliverability fully — how to audit it, monitor it, and recover from it — that is what my deliverability programme is for.
Deliverability for infrequent senders is not about sending more than you should. It is about being smart about what you do in the spaces between — so that when the moment comes, the infrastructure is there to support it.