It would be a great idea to be able to import mail for individual email accounts via POP3 from other servers.

This would be great for customers migrating to you so that they can keep all their email.

Would just need fields such as:
-Hostname
-Username
-Password
-Port
-Encryption

autodiscover for email settings for linux and windows

Most of RBLS are checking the SMTP Banner and currently only the first domain name is being used. To reduce scamming or to prevent being blacklisted you should apply myhostname with the according domain name.

Add Sogo as a webmail alternative in Plesk.

Sogo share your calendars, address books and mails in your community with a completely free and open source solution

Sogo is a great webmail solution and provides native Microsoft ActiveSync support. Mobile devices such as Apple iPhone, Android, Windows Phone, and BlackBerry 10 can fully synchronize emails, contacts, events and tasks with SOGo.

I suggest you add a feature in Settings with which we can enable SPAM / VIRUS protection for newly created mailboxes by default.

Discussion here:

http://forum.parallels.com/showthread.php?287233-Anti-virus-and-anti-spam-enabled-by-default-on-mailbox-creation&p=715980#post715980

We have many support requests from our customers (non technical) to search logs and find if a message was sucessfull delivered and consume much from our support.

If the customer could search logs from a specific sender ou destination, filtering by date, will be great for us.

It would be useful to be able to configure auto replies so that they start automatically on a specific date.

If I don't want to forget to set it before leaving.. or i'm sure there's many reasons!

I would like to use an E-Mail address as an outgoing E-Mail address with no postbox behind it. All E-Mails should be forwarded to another E-Mail address.
Currently you can set up forwarding but if you check "Use postbox" than the mails will be kept on the server although they have been forwarded. If you uncheck it, it is impossible to send emails from that address.

So please add at least an option to delete mails after forwarding them.

At the moment by default any webmail interface is under domain webmail.<domain>

Some people would like to use custom one. For me personally it's important to have this as server-wide setting (I have basic workaround for this - custom domainWebmail.php), but it isn't perfect (many links to webmail service missing, e.t.c.).

And that's why we have plesk - user friendly interface.

enable email piping like in cPanel email forwarders to pipe to a script (osticket)

There is an spam filtering option to "Move to spam folder XXXX" on Linux, but not on Windows (Plesk 11+).

Unfortunately, horde doesn't work so well and every time when a message with broken header arrives, horde displays "Invalid Address" and no subject to all inbox messages. The described fix in https://kb.plesk.com/en/121175 doesn't work in this cases, forcing us to find the broken message manually (or scripting something to do the dirty job).

This feature should exists in Windows env as in Linux.

It would be much better if server-wide and per-mailbox options were available in Plesk to add SpamAssassin rules.

SpamAssassin can be configured by the command line, but this is difficult for many of us.

In light of the Snowden fallout, I hope that Plesk will add support for Mailpile (http://www.mailpile.is) or something similar for secure e-mail.

Actually it's possible to show deferred messages headers in : Tools and settings > mail server settings > mail queue

It would be very useful if it's possible to show the reason why the message is deffered or stuck in the queue (/var/spool/postfix/defer).

I would love to use exchange server 2013 while using plesk panel. Exchange server is by far the most superior email server for windows and would be a great addition to plesk panel.

I believe that there is also an open API or an easy way to send commands which would make it a lot easier to integrate with.

The ability to empty a users emailbox without deleting the account and recreating would be great.

There is relatively new anti-spam tool - Rspamd. I think, it worth to be integrated with Plesk as an alternative to SpamAssassin. It shows better performance as the author says here http://rspamd.com/misc/2016/03/03/rspamd-performance.html

SPF information is so far entered through the TXT record. Adding the emerging new SPF record would make sense.