Dovecot down often, considering iRedMail on Ubuntu 16.04 LTS
Thank you in advance for your time and expertise.
We have had issues with Dovecot going down to the point that the server requires a reboot every week/month. I am not sure if it is running out of memory during backups, if it's tripping on the configuration with Postfix, or if Let's Encrypt is taking it down (issue from another community forum post). We have had a server administrator working on this server for 1 year but cannot solve it.
I am considering moving to iRedMail and, according to the community forum, that can be tricky.
1) Is it practical to increase the space on my Linode, partition a new virtual server and install iRedMail there (to avoid issues with the websites)?
2) Am I replacing one problem with another set of problems?
3) Does iRedMail require a certain stack (i.e. Apache) or does it install what the entire stack it needs? Looks like the server should be "blank", according to link below.
4) Encryption: I see that iRedMail has some level of encryption but they suggest more. Would Let's Encrypt create the same problem? I don't know if iRedMail even uses dovecot or postfix.
This is what I'm following from iRedMail: https://docs.iredmail.org/install.iredmail.on.debian.ubuntu.html
We are trying to avoid Gmail because of the number of email accounts and forwards we have.
3) According to this link, it comes with Nginx
According to this link:
iRedMail uses BOTH postfix & dovecot. It doesn't sound like you're going to gain much here except having to deal with a foreign support organization (read the web page carefully…it was written by someone for whom English is not their first language).
You don't say anything about the characteristics of your Linode… If you think it's a memory issue, have you tried up-sizing it temporarily to see if your problems go away?
I've been using postfix/dovecot for years and have bolted on several custom features to the delivery pipeline and I haven't had a single problem that I couldn't trace back to my own stupidity! Granted, I probably have a lot less mailboxes than you but I've found the postfix/dovecot combination to be rock solid. I have a friend who offers email service for sale to a collection of businesses in a half-dozen domains (I do consulting for him once in awhile) and he reports the same (he has a physical box…some sort of office-type server running Fedora).
Lastly, I would try spinning up another Linode and adding services in an extremely-controlled and documented manner until you believe you have an equivalent system to the one you have. Your problem might not be postfix/dovecot at all…