SMTP 550 after boot from backup


My mailinabox Digital Ocean droplet broke recently as the harddrive let to 100%. I ended up resizing it and booting from a backup to get it up and running, however mailinabox wasnt happy and keeping failing (would work for a bit then would stop serving the admin and recieving emails). I updated the system after rebooting from my backup again and its now up and running…

BUT… I can no longer send emails from mac mail or the browser webmail and produces SMTP 550 errors on sending even though mac mail shows I’m authenticating ok with the server. I can recieve email fine.

Any advice would be AWESONE! Thanks

Is there more specific information together with the SMTP 550 error? Can you put the complete error report here?
Also, can you check the admin page status panel for errors and warnings?

nothing out of the normal. One fishy thing is though that I upgraded the mailinthebox version and it had a UI change (to black) but still complaining its not upgraded.

:heavy_multiplication_x: A new version of Mail-in-a-Box is available. You are running version v57a. The latest version is v65. For upgrade instructions, see

For the upgrade to v65 you need to use a vps installed with ubuntu 22.04. V57a is the latest version supporting 18.04 so that’s explainable.

Do you have more info on the 550 error?

where would i find those errors. The 550 pops up when using the webmail interface, and i dont get anything useful out of mac mail on no send

I’m struggling to place this error, but perhaps it rings a bell for someone else. Perhaps you can provide a screenshot?

Found this hope it helps:

SMTP error 550 usually appears when there is an issue with the authentication of the SMTP client and the SMTP server; in most instances, it means that the authentication is missing. However, there are many other reasons to cause this error; these reasons come with the error code for additional information on the exact cause.

For example:

Email error "550 Authentication is required for relay" indicates that the client requires authentication.
Server error "550 this domain is not hosted here" indicates that the recipient address is not found or is inaccessible.
Server error 550 or 550 Blocked Error indicates that the recipient is blocking your email on the recipient's email server.

Solution - Here’s How To Resolve It

To fix these common issues, the user must pay attention to the description that follows the error code. However, the following common causes would require different resolutions.

Email error "550 Authentication is required for relay" - The user must check the configuration for proper authentication on the email client.
Server error "550 this domain is not hosted here" - The user must ensure that all the recipient email addresses are valid.
Server error 550 or 550 Blocked Error - The user may need to check with the recipient to ensure that the sender's email domain or email address is not within a blocklist.

Good luck

I remember that I was receiving 550 errors when I messed with the /etc/postfix/ .
I was setting up relays or something. There is an authentication section there. It might help if you inspect it or find yourself a default one and try again. Tail the mail log when the 550 error occurs when sending mail. like this tail -F /var/log/mail.log

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