SMTPUTF8 - Messages not received

I’ve been running MIAB for a long time, but in testing a new mail sender for work (sender=MailGun), messages to my box are being rejected:

“SMTPUTF8 is required, but was not offered by host”

Of course I did search the forum first and found a couple of closed posts, but have not found a solution to this.

Has anyone encountered and solved this?

I’m on Version 0.51at present

I have never come across this problem.

Maybe this U&L answer is useful:

you need to edit /etc/postfix/ and set


this gets overwritten whenever you update/upgrade mailinabox

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Thanks. I’ll look into both of those. Turns out the ancient mail sender (ASPEmail) needed excplicit UTF encoding added to any and all header fields (subject included).

The body was never a problem but the subject become the issue.

Having an issue where we can’t send or receive emails now. It was working until recently. Everything is configured correctly.

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