Over time your database may increase, and some particularly heavy mailings (with a large number of emails) may see the stats drop.

Sometimes it is your activity that triggers blacklistings directly in some email clients (Gmail, Microsoft...).

When all your settings are set and you already fine-tune your shipments, a method can effectively and durably improve your deliverability: remove the least qualified contacts from your normal mailings (high-speed) and email them afterwards at low speed.

By sending to your optins contacts, you benefit from open rates and high clicks - which improves your reputation with servers - before sending to your other contacts. Gradually when these contacts open an email, click or subscribe, they will pass in the fast sendings.

Example with 2 similar newsletters with a long interval

We tested on the same tool, same SMTP relay.

1^st step - Sending the 1^st test email: to qualified contacts

We sent an email classically to a specific target 3 months ago (the reference email).

Then our 1^st test email, to contacts who clicked at least once in last 12 months.

:

Three months after the reference email sent to 114 623 people, we send the first test email only to the clickers of the last 12 months, only 20 668 emails.

First advantage: the drop of the new target (18% of the original target) already allows us to reduce the speed of sending.

Two days later we are already seeing comparable number of openings and clicks:despite very different target sizes (114 623 emails / 20 668 emails).

:

When the 1^st test email is finished, the trend is confirmed. Numbers of unique hits are very close.

2^nd step - Sending the 1^st test email to low-qualified contacts

On 9 march 12h38, we will send our test email to other contacts: We just use the same email and change our filters, to send only contacts that have not clicked during 12 last months.

Before sending, we greatly reduce the speed of sending: 100 emails/h.

Now 16 march 12h27 we have this stats:

Uniques opens are:very close and unique hits are superior! This for a cost 3.7 times cheaper.

Furthermore we see even several months after sending, stats still move (as email ID 192). So we can be sure that stats from email ID 236 will still increase and unique opens will be superior also.

Another advantage is that by doing so you keep good opening stats throughout your shipment, and therefore a good reputation.

In this example newsletter, after sending to qualified contacts (20 668 emails), and sending to non-qualified contacts (9760 for now), we recovered 248 new openings. So many contacts who are now considered qualified, and who will increase the first mailing of the next newsletter.

Stats by cost