One general question: I have a server on a shared host which IP constantly gets on blacklists of some mailservers (live.com, hotmail, ...).

That means we can receive emails but cannot send emails to those providers.

Months of unblacklisting, communication with the provider does not seem to be a durable solution.

I've found one solution that seems to be pragmatic and working: We simply change the smtp relay in the mail clients to another provider (e.g. Mailjet) and add SPF / DKIM TXT records to the main domain.

So far everything seems to be fine, the emails get delivered (because the mails are sent from another IP). Are there some caveats to that approach or is this common practice?

  • You don't have to use an SMTP relay, you can simply change to using a different SMTP service. I think that's what you mean, rather than a relay. For example for years I used AuthSMTP to deliver my emails as HostGator servers were regularly on blacklists. – Tim Jul 16 '18 at 8:22

As long as you're a customer of those services, and using them within their ToS, yes, it's perfectly acceptable to use a third party to relay your email. It's very common in the enterprise, with services like Mimecast, etc.

Even if you are using a third party mailer, I would suggest you host yourself on a platform where a) they don't have such a poor reputation due to failure to manage their bad clients; b) you have your own fixed IP. If you're supposed to be a professional organisation (can't tell from this question), then using a dynamic IP is giving the opposite impression.

When I used to run gateway mail services for an organisation, I blacklisted anything coming from what appeared to be a dynamic hostname by rote. I think in about 8 years, we had less than a dozen "false positives" (an internal recipient wanting to receive mail sent from their spouse from a dodgy server being the most common scenario). That's how bad dynamic mail senders look - there's nothing to distinguish your dynamic IP from some botnet like Comcast or Brazil Telecom home users.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.