Almost every deliverability problem on a new platform comes down to the same three things. In order of how often they are the cause:
1. Your DNS records are not right #
Three records decide whether a receiving mail server believes you are you.
SPF says which servers may send on behalf of your domain. If it does not include the sending infrastructure, receivers see mail claiming to be from your domain arriving from somewhere unlisted.
DKIM signs each message cryptographically, so the receiver can verify the message was not altered and did come from an authorised sender.
DMARC tells receivers what to do when SPF or DKIM fail, and asks them to report back. Start with a monitoring policy, read the reports for a couple of weeks, then tighten it.
We set all three up for you. If your DNS is managed elsewhere, we send you the exact values. Do not guess at these: a single wrong character in an SPF record fails silently.
2. You sent too much, too soon, from a new setup #
Sending reputation is built over time, per domain and per sending infrastructure. A domain that has never sent from this infrastructure has no history, and a sudden ten thousand messages looks exactly like what a compromised account looks like.
Warm up instead. First mailing to your most engaged segment, a few hundred addresses. Wait a day. Watch the open rate. Then double it. Within two weeks you are at full volume with a reputation that supports it.
3. Your list is older than your consent #
This is the uncomfortable one. If a meaningful part of your list has not opened anything in two years, sending to them produces bounces, spam complaints and no revenue, and it drags down delivery for the people who do want your email.
Before your first big send, segment out everyone who has not opened anything in the last twelve months. Send them one re-engagement message. Whoever does not respond, stop mailing. You will lose list size and gain delivery.
Checking your work #
Send a test to an address at a large provider and look at the message headers. You want to see SPF pass, DKIM pass and DMARC pass. If any of the three says fail or none, fix that before you send anything real.
Ask us and we will check it with you. It takes ten minutes and it is the single thing most worth being certain about.
