Using your own SMTP server

Applies when your sending is: Your own SMTP server

Issue Mint sends through any SMTP server. You give it a host, a port, a username and a password, send a test, and issues go out over your connection from then on, under your own sender reputation rather than ours.

There is one limitation, it is not small, and it is the reason Amazon SES is recommended instead: an SMTP server tells Issue Mint nothing after the connection closes.

What Issue Mint asks for

Issue Mint asks for the host and port, a username and password, and which encryption the server expects.

Port 587 with STARTTLS is the default in the form because it is what most servers want. Port 465 with SSL or TLS is the other common pairing, and a plain unencrypted connection is offered for a server on your own network. The password is encrypted and never shown back, so leaving the field blank when you re-save keeps what is stored rather than clearing it. You also set the from name and from address here, and with a domain connected the address has to be on that domain, which is covered in from name, from address and reply-to.

Saving working details is the whole of the decision. There is no separate switch for which way a newsletter sends, and no setup pipeline to sit through either: SMTP has nothing for Issue Mint to configure on your behalf, so the next step is a test send.

The limitation, plainly

An SMTP server accepts a message, closes the connection, and never reports back. So Issue Mint does not learn that an address bounced, and does not learn that a reader marked an issue as spam.

That feedback is the mechanism by which a list looks after itself. Amazon SES sends bounce and complaint notifications to a topic Issue Mint listens on, which is how a dead address stops being mailed without anybody noticing it. Over SMTP that channel does not exist, and no amount of work at our end creates it.

What that means for your list in practice

Your delivery numbers become a floor rather than a measurement, and cleaning the list becomes a job you do by hand.

Issue Mint still records what happened at the moment of sending, so a message your server refused outright is counted as failed. What it cannot record is everything that happens afterwards, which is most of it: a mailbox that accepted the message and then bounced it, a full inbox, an address that has been closed for two years. Watch your own provider’s reporting for those, and take the addresses off in your list when you find them. Reading delivery figures with this in mind is covered in reading delivery numbers.

Why Amazon SES is the recommendation

Because it is the arrangement where your list stays clean without you thinking about it, and it is usually the cheapest at any real volume.

Issue Mint sets SES up for you rather than handing you a checklist: it creates the domain identity, the configuration set and the notification topic in your own AWS account, and it wires the bounce feedback back to us in the process. The result is your own reputation and your own bill, with the list hygiene you had while we were doing the sending. That is the case for it, and what sending gives you makes the same argument from the product side.

How fast SMTP sending goes

SMTP sending runs at 10 a second, deliberately.

Amazon reports what an SES account is allowed, so Issue Mint can read that number and stay under it. An SMTP server cannot be asked, and guessing high on somebody else’s server is how a send gets throttled or refused halfway through a list. So the rate is cautious and fixed, which for a list of ten thousand is under twenty minutes.

When a test send fails

The message on the Sending tab is your server’s answer, translated where the raw version is unhelpful.

• The username and password were rejected. The credentials are wrong, or the server wants a different form of them, often the full email address rather than the local part.
• We could not connect. The host, the port or the encryption setting is wrong. Try the other port and encryption pairing before anything else.
• The secure connection failed. Same fix: 587 with STARTTLS, or 465 with SSL.
• The server refused that from address. Most servers only send as the mailbox you authenticated with, so the from address has to match it.

Issue Mint also opens a bare connection to your server once a week to check the details still work, and emails you if they have stopped. Until they are fixed publishing is locked, and an issue you had scheduled goes back to draft with a note rather than waiting, so it needs rescheduling once the server is answering again.