• RoundCube webmail by Default provide a Vacation auto reply
• The option should not be hide in settings.
• Able to setup start and End date.
• Possible to set a limit to one message per day for each account.

An option to customize outgoing SMTP port.
Both for SMTP relay and direct SMTP.
Currently there's only a temporary workaround for Google Cloud VMs with Plesk.
This configuration might be overwritten by an update:
https://support.plesk.com/hc/en-us/articles/115004060494

Details: SA should filter forwarded spam emails just after they delivered to the end-point mailbox and block the sender of spam messages.

Plesk does not currently support DNS Whitelists like it does RBLs, such as the list at dnswl.org. There needs to be a way to add this from the Plesk UI.
The Postfix main.cf config directive is permitdnswlclient.
Whenever a Plesk upgrade happens, the setting, if added is removed and needs to be added back manually.

It would be really nice, if you can ad a autoresponder funktion with additional features like

-startdate
-Timefunktion (start at 8.00 or finish 17.00 h)
-repeat function (example: every monday and tuesday)
-activation per app
-html in content area

Thanks

For better SPAM Protection it would be nice to add an Option to let the Mailserver check, whether senders Domain is existing or even not.

I got Mails from "Domain.xyz" wich is of Course no valid TLD.
"Reply-To" is of Course an valid Mail adress.

On request, my Data-Center told me they could activate that Option, but while Plesk is Controlling that config, on next Plesk update the Change gets lost.

So: Could you add in Plesk that Feature as an Option?

Implement push notifications to iOS devices from mail server.

Here are details of what I mean: using a patched version of Dovecot and a small Perl script, it's possible to get native Apple push notifications for new mail using the stock iOS mail client. This is accomplished by mimicking Apple's XAPPLEPUSHSERVICE IMAP extension for Dovecot used in macOS Server, whose source code is published on the Apple Open Source website. See more details here: http://bit.ly/2H8NERJ

Don't send auto responder to adresses with "noreply" or "no-reply"

By default, the Mail Audodiscover function does not set the Root folder path to "INBOX" in Outlook, which results in an odd directory structure:

Inbox
Drafts
Sent
Trash
Spam
Outbox

Please provide a way to configure this without having to manually edit the mail server configuration files.

It'd be good to be able to migrate Contact & Calendar from cPanel to Plesk.

Please add functionality to access webmail from Plesk interface without using a password.
The same functionality is enabled in cPanel. Please see section "Access webmail from the cPanel interface" of documentation:
https://documentation.cpanel.net/display/CKB/How+to+Log+in+to+Your+Server+or+Account#HowtoLogintoYourServerorAccount-AccessWebmaildirectly

Add a feature that allows the configuration of Postfix relay to Exchange for a specific domain.

For example, all outgoing emails from @example.com are relayed to an Exchange/Office 365 server.

By default use an existing email created by default as a return path . Return path should be configured in mail tab instead of solution from here:
https://support.plesk.com/hc/en-us/articles/115000419013-What-is-the-return-path-sender-in-PHP-mail-scripts-and-how-to-change-it-

It's required to send Plesk notifications using external Mail server at the same time keep local mail server(postfix) working for domains.

In Plesk Windows, by default, mailing lists are created with the sender address of moderator instead address of mailing list.

So to fix the issue, and change the address of mailing list to mailing lists address instead moderator address, we need to acess the server via RDP, and change this configuration in MailEnable list settings.

I suggest to implement this feature directly in Plesk control panel.

Use case: One of our customer has uploaded files to his ftp server in a public internet cafe and his password was stolen. Afterwards there was a mass spam mail sending script on his webserver. Our server has been landed in black lists. It was very difficult to find and correct it.

Hello,
I miss the functionality of managing a blacklist of target email addresses in case you have a catchall email domain.
In most cases, the originator address of spam emails changes every time, but the target address is frequently used.
So with this functionality, I could drop out invalid recipient addresses, without giving up the setup to use catchall all emails <everything>@your-domain.
This is useful to register webshops or community everytime using a separate target email address to distinguish incoming email if they are valid or not.

Any kind of wildcard mail aliases (regex and/or /?) would be highly appreciated in order to realize a "allow form all but anything like..." handler. Example: Ban all info-@domain addresses.

I had somenting similar at my old provider but not with new one using plesk. Now I need to insert dozens (hundreds) of addresses one by one...

If there is already a way to realize something similar I was not able to find it (or my provider did not enable it)...

Add GUI for email greylisting per email account in Plesk Onyx. Also add a 'Detection Only' mode to allow a testing period, similar to spam filters and mod_security.