Hi all,
I've been running postfix for years, and once before this issue came up but I never saw it again. But It's no surfaced again and has happened a couple of times over the last few months and I'm at a loss. Firstly : Postfix Version 3.4.13 OS : Ubuntu 20.04.5 LTS So what seems to be happening Is that if something causes a dns issue postfix stops sending mail, and outgoing mail queues with things like this. (Host or domain name not found. Name service error for name=gmail.com type=MX: Host not found, try again) Also incoming mail is also affected, but not completely. Some does still show up. Now once I notice the issue (or someone tells me) postqueue -f does not work.. I end up having to reboot the box then run postqueue -f to get the que to process. Before I reboot the box, I can run dig commands to the cows come home and everything seems to be fine yet not fine with postfix. So what I don't get is , ok so I had a dns issue (maybe both my internal servers happened to get rebooted for updates close together or something), but why when they come back does things not start working again ? And why does it only impact some incoming mail and not others? I changed my yaml interface file to point to not only my internal dns servers that I run, but also my 2 routers which have resolvers on them that point to other servers. But it happened again today.. I don't get it. Has anyone seen this before ? is there a fix ? is it really a postfix issue ? or is it Ubuntu that is having the issue ? I get DNS is important, but things can happen, and I would expect that things would start functioning normally and not require a reboot to "clear" the problem. Thanks for any thing you can provide. Dave
