Self hosted email... well, not really

Hi,

I was having a Google Suite for Education account with loads of storage, big G then lately decided to reduce the storage to 10GB only and my mail box alone was already bigger than that. Right now, I have backed up old email using Thunderbird, but I am less than happy with the solution because it is on one given machine, but also, Thunderbird is EOL.

I quickly passed through the consideration of having my own server as it gives me quite a headache between the required uptime so that I do not miss any email, but also, the black-list management that can become really pain in the rear.

So what I would like to achieve now would be the following :

• a "mail" server with all emails stored on it
• this server is accessible through a webmail, even better if there is an Android app
• This server connects to Google, Outlook and all my other email addresses to download the emails from there.
• This server uses the SMTP from Google, Outlook... as I configure them

Basically, a Outlook or Thunderbird in a web-based format.

I would like to achieve that with a Docker based solution so I can map volumes to it and easily get that backed up, but it is not a totem.

Does such a solution exist already, or does anybody have some pointer to put that together?

Right now, I identified a web-based email client that would work (Roundcube), but I still need a server that would fetch the emails, store them and relay the outgoing to SMTP. I can see full email solutions, but I am not sure it could fetch email from another server through IMAP or even POP.

Thanks