Identifying suspicious sending behavior is the name of the game for ISPs trying to protect their networks from bad actors. They’re constantly updating algorithms and leveraging machine learning to identify spam and preserve the inboxes of users. To avoid being caught up in the same net, legitimate senders need to avoid red flags on their own sending activity. At no other time of year is this more critical than the holidays.
Why talk about Christmas in July? Because sending volume matters. To ensure the success of larger campaigns during the holiday season, you have to start planning and prepping your lists. Now.
In the eyes of ISPs, good senders are consistent. They have consistent open rates, consistent positive engagement with their recipients, and are sending consistent volume to their networks at regular intervals. Unfortunately, make-or-break holiday revenue will cause some marketers to ignore these practices and roll the dice with abnormally large volumes of mail. This typically manifests itself by senders overriding the engagement criteria on their campaigns, and batch-and-blast mailing to entire lists of subscribers with heavy frequency, fatiguing subscribers.
It’s My List, Why Can’t I Mail as I Please?
The most obvious problem with this type of mailing behavior is that it is not consistent with the behavior a sender exhibits throughout the rest of the mailing year.
Consider the ISP’s perspective: A known sender to their network suddenly doubles, triples, even quadruples the amount of mail hitting their servers for a single campaign—and at a much higher frequency. Not only does the ISP detect a spike in volume, but spam trap hits increase, hard bounces increase, and a wave of fresh spam complaints are generated by the change in activity. Must be spam. Block.
Opening up campaigns to entire mailing lists means opening up sender reputation to a host of issues. ISPs determine reputation by 24-hour, 7-day, and 30-day performance trends, so week-to-week and month-to-month volume fluctuations are critical. If an ISP notices any dramatic deviations from a sender’s volume patterns, it will raise a red flag.
Slow and steady wins the race: By starting increases now, peaking around 2-3 weeks prior to the start of holiday mailing, this activity will appear normal to the ISPs receiving it.
So, What Can I Do?
If larger sending is on your holiday horizon, now is the time to start expanding your lists in small chunks.
Segmentation should remain a key consideration as you expand:
- Users who have opted out should never be included in campaigns.
- Riskier segments—with lengthier and lengthier lapses in email engagement—should be monitored carefully. As segments trigger negative metrics (e.g., hard bounces, spam complaints, etc.), they should be removed from regular sending unless they can be re-engaged.
Actively weed out inactive addresses:
- Plan re-engagement campaign cycles now so users are active and up-to-date for holiday mailings.
- Use a confirmed opt-in to eliminate unengaged users from entering campaign lists right out of the gate.
- Users who decline to confirm an opt-in or re-engage should be removed from your lists.
The last thing you want to face is a blacklist or block going into the holiday season. Reputation damage, once it occurs, requires weeks of consistent sending to correct. Often by the time the damage is inflicted, senders don’t have time to recover before the holiday mailing season. Slowly increasing mailing volume, meticulously reviewing metrics to weed out and remove risky segments and contacts, and adhering to confirmed opt-in guidelines will help line up a successful holiday season.
