we have qnap 459+ nas device with embedded linux on it
you need to check this system via temviewer to see if you can do it first
what we like to do is to have GETMAIL latest version installed and make it work so that we can use the getmail ALL MAIL feature which would download all folders auto ... getmail have the be the latest version not the older version ..
and use rainloop and roundcube to check our emails ...
so you will install
Rainloop github version using git
roundcube github version using git
so all will be latest versions for us to be able to check our mails and reply etc using the email clients ..
Spam control ? will you need to install extras for that ? you can mention this in your proposal please.
Getmail will download our emails and save into Qnap ,.. not sure if we need XDove to do this , Xdove is already available in the QNAP Apps so installing that with an interface wont be an issue ..