Troubleshooting postfix using bcc to local user

After routing mail through postfix to an external relay server (in this case gmail's smtp relay), all the mail from a server was routing correctly. Except after a couple of days I noticed a couple of strange bounces. Authentication at the gmail end was by IP address and domain, so any address [email protected] could be used to send email. But these were coming from [email protected] so were being rejected with a helpful message by gmail.

The IP address you've 550-5.7.1 registered in your G Suite SMTP Relay service doesn't match domain of 550-5.7.1 the account this email is being sent from. If you are trying to relay 550-5.7.1 mail from a domain that isn't registered under your G Suite account 550-5.7.1 or has empty envelope-from, you must configure your mail server 550-5.7.1 either to use SMTP AUTH to identify the sending domain or to present 550-5.7.1 one of your domain names in the HELO or EHLO command. For more 550-5.7.1 information, please visit 550 5.7.1 https://support.google.com/a/answer/6140680

Pretty helpful as messages go. Less helpful was the fact that there were several websites on the server and a couple of other apps, and I didn't have access to the admin panels of any of them. The mails, once bounced, were removed from postfix's queue, never to be seen again. Time for some detective work.

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Digital Ocean spaces vs restic

Very easy answer to a problem that's probably had you cursing for ages. When you set up a DO Spaces instance, you get a URL like https://myspace.eur3.digitaloceanspaces.com/, where eur3 is the datacenter you're in and myspace is the space name you supplied. So you just take that and append s3: to it in your restic … Read more

Roundcube 1.38 add plugin (on Ubuntu 18)

File locations are a bit all over the shop in this version, so this is how it works out. For reference the actual program files are downloaded to /usr/share/roundcube/ the config happens in /etc/roundcube the web directory is in /var/lib/roundcube, which contains symlinks to the above locations. This is the one you add to your … Read more