This is where you'll find an overview of the best ideas.

Vote
260
points
Future Mail Posted by himanshu.goyal to Mail-Features, 24 Apr 09 at 10:27
In future date if a person wants to send a mail right now he should be able to do that. For example today is 24 march and my friend birthday is on 27 march , then i should be able to schedule the mail today itself so that it could be sent on that day at a particular time. [....]
Vote
89
points
Support for encrypted mail Posted by AT to Mail-Features, 27 Apr 09 at 16:52
GMX is a really good free e-mail service but it would be nice to see it supporting encrypted mail. [....]
Vote
88
points
Reading confirmation Posted by Frosine to Mail-Features, 28 Apr 09 at 14:45
Maybe the question has already been asked. Is there a possibility to check if an email I've sent has been read ? Or possible to get a confirmation if read ? [....]
Vote
83
points
free SMS function Posted by Sebstr to Mail-Features, 21 Apr 09 at 18:48
A free international SMS sending feature would be a real treat. Any chance?

Kind regards,
Sebastian [....]
Vote
75
points
mail delivery receipt/mail read receipt Posted by astro to Mail-Features, 21 Apr 09 at 12:49
Notification that mail has been delivered safely to an address, and the option for notification that the mail has been opened/read is useful. It's available with British BT webmail, but I prefer GMX! [....]
Vote
72
points
Push E-mail Posted by Luke Whiting to Mail-Features, 13 Apr 09 at 19:59
For GMX to implement push email, Ideally via the Microsoft Exchange protocol that is compatible with almost all smart phones including the iPhone.

Details of a proposed implementation that is compatible with GMX's existing set-up is available at the following forum post:
http://forum.gmx.com/forum/posts/list/1974.page

This idea seems to have quite a lot of support on the forums already so thanks to all of you! [....]
Vote
70
points
A Way to "Flag" Important Emails Posted by homebiz1@gmx.com to Mail-Features, 22 Jun 09 at 23:32
Ala Yahoo, Gmail, and even Mail.com, it would be Great to have a way to "Flag" important emails, , or Mark them as "Important" [....]
Vote
53
points
Too many mails Posted by Stuart to Mail-Features, 25 Sep 09 at 19:16
Allow more than 10 email addresses to be included on an email - I understand the system limits an email account to 10 per email, then when that is hit the system does not allow any further emails to be sent for one hour. This is ridiculously low, increase it to at least 50 - spam or fraud emails will still be prevented at this level, but a limit of 10 on an email is silly and frustrating. [....]
Vote
50
points
Add a signature Posted by september to Mail-Features, 8 Apr 09 at 11:54
I am delighted with GMX if fulfils most of my email requirements, I would however like to be able to assign a different automated signature to all my accounts in mailcollector. Each account has a different purpose so the same signature would not be appropriate.

Thank you [....]
Vote
46
points
Improve speed of file attachments Posted by filbert to Mail-Features, 27 Apr 09 at 22:47
When attaching files to an email, the process of scanning and attaching is extremely long. I was uploading a 2mb file and was waiting up to 15 mins for it to attach. I had to use another email provider in which the uploaded about 10 times faster. It would be great if the problem could be solved. [....]