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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RTL8188 adapter upgrade hell

On my desktop I've been running Linux Mint for the last few years, and have always done the distro upgrade-in-place. This time I tried it and there were too many errors — the upgrade tool wanted to remove around 50 apps, disable all my repos, and generally mess around with my system in too many ways, so I opted to go the "wipe and install fresh" route. My reasoning was also that after 6 years of upgrades, there were probably a few extra files on there, that I didn't need ( a mysterious 3 Gb in the flatpak directory for eg), and I'd messed around with the system config a few times over the time — pipewire, different DNS resolvers etc — so a fresh install would be a good thing. And it was, but for one nightmare: my RTL8188 adapter.

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Node Package Manager install surprise. 387 extra packages!

I've got a server running Ubuntu 20, and wanted to try out something on it with nodejs. I checked on the server and apparently nodejs was already installed. I guess some previous dependency had put it on there a long time ago. node –version v10.19.0apt-cache policy nodejs nodejs: Installed: 10.19.0~dfsg-3ubuntu1 Candidate: 10.19.0~dfsg-3ubuntu1 OK, so the … Read more