The steps below are the ones we see make the biggest difference. Most of them take a few weeks to show results, so start now. Our deliverability team monitors your traffic throughout the season, and the better prepared you are, the less there is to fix.
1. Get authentication in good shape
Gmail, Yahoo, and Microsoft all require bulk senders to authenticate their mail, and unauthenticated mail is the first to be filtered when volume peaks. Check these before the season, not during it:
| Record | Target | Why it matters |
|---|---|---|
| DMARC | p=quarantine or p=reject, with an rua= tag for reporting | p=none only monitors; enforcement protects your brand from spoofing |
| DNS TTL | 3600 seconds (1 hour) or more | Very short TTLs mean more lookups, and resolvers can fail to return your records at peak, especially for Microsoft sends |
Omnivery checks that a minimal required DMARC record is present, but not that it is enforced at p=quarantine or reject, which provides better protection for your domains. Additionally, without an rua= tag in the DMARC record, you are missing out on the best benefit of having DMARC in the first place (the reporting aspect).
If your DMARC policy is still at p=none, review your DMARC reports first and make sure every legitimate sender passes. Then move to quarantine, and later to reject. Make any of these changes now, in October. Don't rotate keys or tighten DMARC in the middle of November.
2. Separate marketing and transactional mail
Order confirmations, shipping updates and password resets must arrive on time, and Black Friday is when they matter most. If they share a reputation with your promotional or marketing mail, one bad campaign can delay every receipt.
Keep the two streams clearly apart:
- Different sending subdomains, for example news.yourbrand.com for marketing and mail.yourbrand.com for transactional. Each builds its own reputation.
- Different sender addresses, so recipients and mailbox providers can tell an offer from a receipt.
- No promotions in transactional mail. A large discount banner in an order confirmation makes it marketing in the eyes of filters and the law.
In Omnivery, set up each stream as its own sending domain so its delivery and reputation can be tracked separately. Contact us if you want to review your setup before the season.
3. Secure your signup sources
Every bad address that gets onto your list costs you later. The weeks before Black Friday bring a rush of signups from contests, discount pop-ups and checkout forms, and also bots, typos and spam traps. Protect every form that feeds your list:
- Email validation: check the address before accepting it. Signup is where typos and fake addresses enter your data, so it's where Omnivery email validation is most valuable: it rejects syntax errors, dead domains, disposable addresses and role addresses in real time.
- reCAPTCHA or a similar challenge: stop bots from flooding your forms with fake or malicious addresses.
- Typo catching: suggest a fix for common domain mistakes, like gmial.com or yaho.com, before the form is submitted.
- Double opt-in (DOI): send a confirmation email and add the contact only after they click it. This is the strongest protection against traps and fake signups.
- Include the signup source: in the event that you are seeing issues crop up from a particular source, identifying that source clearly can help you remove all contacts from the poor quality source at once.
4. Prune your list and build engagement cohorts
A smaller, engaged list delivers better than a large, stale one. Before the season, remove addresses that only hurt your reputation. This step is especially relevant if you skipped Step 3 above before now:
- Long-term inactives that haven't opened or clicked in 6-12 months (adjust for your purchase cycle).
- Suspected spam traps: old imports, addresses never confirmed, and obvious typo domains.
- Role addresses (info@, admin@) that were never actively subscribed.
Omnivery email validation does much of this cleanup for you. It catches syntax errors, domains that don't resolve or accept mail, disposable and throwaway domains, and role addresses. It's enabled per sending domain, and you are able to switch this on in your domain settings within Omnivery. Treat its result as a strong signal rather than a guarantee: some mailbox providers accept every address at first and reject mail later.
Then split the remaining audience into cohorts by engagement, and send to each at a different rate:
| Cohort | Last real open or click | Suggested approach in the busy season |
|---|---|---|
| Most engaged | Last 30 days | Every campaign, including early access and first-wave offers |
| Engaged | 31-90 days | Regular cadence |
| Cooling off | 91-180 days | Reduced frequency, strongest offers only |
| Disengaged | Over 180 days | Re-engagement campaign or suppress (see section 7) |
Make sure your cohorts are built on real engagement from Omnivery. Security scanners click links automatically and Apple Mail Privacy Protection fires opens nobody made, so many "engaged" contacts are really bots. Omnivery's Bot Detection flags these events, so you can trust these metrics.
Start your volume ramp with the top cohort and add lower cohorts only while metrics stay healthy.
5. Increase volume gradually
If you plan to send more in November than you do today, raise volume by no more than 20% over the previous day's sends. Mailbox providers read a sudden jump as a red flag, and respond with deferrals, throttling, or spam folder placement.
At 20% per day, doubling your volume takes about four days, and tripling it about a week. Each step only works if engagement holds, so check bounces, complaints, and deferrals before every increase.
- Write down your current daily volume and your planned peak.
- Work backwards from your peak date to set the start of your ramp.
- Pause the ramp if bounces, complaints, or deferrals rise.
- Start the ramp with your most engaged contacts.
- Tell the Omnivery team your planned peak volumes and dates in advance if you need assistance.
6. Send at a slower rate
Spreading a campaign over time is safer than releasing it all at once. Mailbox providers watch how many messages arrive from you per minute. A burst of hundreds of thousands in a few minutes can trigger deferrals, especially at Microsoft and Yahoo, and deferred mail arrives late or not at all.
A slower, steady send also leaves room to react. If early batches show rising bounces or complaints, you can stop the campaign before it reaches the whole list. It also protects your website and customer service from a traffic spike when every recipient clicks at once.
When you send to Omnivery through the API or SMTP, the pace is set by your own application. Throttle it on your side: send in batches, queue messages, and release them at a fixed rate per minute or per second. If you're not sure what rate suits your volume, ask our deliverability team.
- Set a per-minute or per-second limit in your sending application for large campaigns.
- Schedule large sends early enough to finish before your offer goes live.
- Watch the first hour of delivery before letting the rest go out.
7. Re-engaging an older list
Sending a Black Friday offer to an old, unmailed list is one of the riskiest things you can do before the season, and it's the single biggest contributor of spikes in complaints and bounces. Unfortunately, we see this all the time. It's a problem because old lists contain addresses that have been abandoned or turned into spam traps, and people who no longer remember you. A single send can bring bounces, trap hits, and complaints that damage the reputation your whole program relies on in November.
If you want to bring an older list back, do it now, weeks before the peak, and do it carefully:
- Validate the list first. Run it through Omnivery email validation to remove syntax errors, dead domains, disposable addresses, and role addresses before anything is sent.
- Split it by age. Group contacts by when they last opened, clicked, or bought. Start with the most recent group and leave the oldest for last, sending in smaller batches as you go backwards.
- Incorporate inactives into regular sending at a rate no higher than ~5-10% of regular sending volume. Try mixing in some of the less active list members into your typical sending, so you have at least one touchpoint before the busy season begins.
- Send a re-engagement message to inactives who do not engage. Remind people who you are and why they signed up, and ask whether they want to keep hearing from you. Make unsubscribing easy - unsubscribes are always better than complaints. IMPORTANT: send this re-engagement message in chunks over the next several weeks, making sure that each "chunk" is less than 5% of your overall daily sending volume. Never send a bulk reactivation email to inactives. This is done to avoid high bounce spikes from sending to unengaged recipients.
- Send in small batches at a slow rate. Check bounces and complaints after each batch before sending the next.
- Keep only the people who respond and/or do not bounce. Count only real human opens and clicks, not bot activity. Suppress those who don't respond after two or three attempts.
- Stop if the numbers go wrong. If a batch shows high bounces or complaints, stop and don't send the older groups at all.
If the list hasn't been mailed in more than two years, talk to us before sending anything. In many cases it's safer not to send at all.
Checklist
- ☐ Check DMARC (quarantine or reject, rua=) and SPF and DNS TTLs (3600+).
- ☐ Keep marketing and transactional mail on separate streams.
- ☐ Protect every signup form with validation, reCAPTCHA, typo catching and double opt-in.
- ☐ Remove bounces, long-term inactives, and suspected spam traps.
- ☐ Build cohorts on real, bot-filtered engagement.
- ☐ Plan your volume ramp, no more than 20% above the previous day, and share your peak plans with us if you want assistance.
- ☐ Throttle large campaigns in your sending application.
- ☐ Re-engage older contacts now, or leave them out of the season.
Want help preparing your account? Contact the Omnivery deliverability team using support@omnivery.com.