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FAQ – answers to frequently asked questions

FAQ – Answers to frequently asked questions

You can set up access to the central mailbox server yourself in your mail programmes (e.g. Thunderbird or Outlook) and smartphones. To quickly check your mails, you also have the option of accessing the central mailbox via the browser with Webmail.

The size limitation lies in the transmission capacity of the networks, in the storage possibilities of the mail servers involved and in administrative restrictions. These conditions vary greatly throughout the e-mail providers.

For sending and receiving e-mail, a limit of 200 MBytes per e-mail is currently set. This means that you can send a file of approx. 150 MBytes, for example. For webmail there is a limit of 100 MBytes per attachment.

If you want to send larger files, use a secure cloud service to which you upload your file(s). You then send the recipient the address where your file(s) can be accessed. Recommended services are:

There is also a size limit for receiving email on the central mailbox server – the maximum size of your mailbox, see Quota in the IdM portal.

For security reasons, e-mails with attachments that could be potentially dangerous are not transported. This applies to attachments with endings such as .exe, .com, .bat, .cms, .scr, .msi, etc. – see blog article (in German).

E-mails to be sent, like received messages, are checked by anti-virus and anti-spam programs.

In case of problems, please use for data exchange

You can send e-mails to a maximum of 150 recipients per hour. It doesn't matter if it's one email or 150. Justified exceptions are possible, of course. You can find explanations in the blog article (in German).

In most cases, e-mail is transmitted in seconds or minutes. However, if a transmission server is not available (network malfunction, server overload or failure, misconfiguration), delivery is delayed. The central mail relays of the TU are currently set in such a way that if delivery is prevented, they send a short message to the sender about the delay after 24 hours, and another message after another 24 hours:

Ihre Nachricht an                        Your message to
                    user@tiefschlaf.net
konnte bisher nicht versandt werden,     has not yet been delivered.
sondern steht noch in der Mail-Warte-    The message is queued for processing
schlange am Mailserver                   on the TU Chemnitz mailserver
                    ....hrz.tu-chemnitz.de.
...

If the mail still cannot be delivered after 5 days, it is returned to the sender.

Since there is (still) no reliable feedback on the delivery of a mail to the recipient, one should agree with the communication partner on a short feedback after receipt for important messages.

Spam-Mail Sometimes unwanted spam mail lands in my mailbox, which at first glance is not intended for me:

Why does this e-mail reach me anyway?

In addition to the message header (header lines To:, Subject:) and the actual content, an e-mail also consists of an envelope containing the sender and one or more recipients.

This is like a business letter – there the letter also has a letterhead, which often contains the sender, recipient, date, subject, a logo, etc. This is then put in an envelope with the recipient and sender written on it (and a stamp stuck on it). Only this address information on the envelope is used by the post office for delivery.

The e-mail transmission system also uses only the addresses on the "electronic envelope" to deliver the mail. Normally, the addresses on the envelope and in the header are identical (analogous to the window envelope in letter post). In the case of spam mails, however, the envelope addresses are often set independently of the header (which usually contains forged addresses). This is intended to disguise the origin of the dubious message and make the recipient feel insecure.

Incidentally, the complete headers of an e-mail (in the e-mail program with the function "message source text") also contain information of the "envelope":

Return-Path: <dehumxxxxx@worldwide-database.com> 
   - the envelope sender, this is also usually faked in spam mails.

Received: from [81.91.65.XX] ... by abcde.hrz.tu-chemnitz.de... for user@hrz.tu-chemnitz.de; Tue, 16 Sep 2003 11;12:01 +0200
The "receipt stamp" of the e-mail to the TU Chemnitz, here the sending computer, the "envelope recipient" and the time appear.

When deleting e-mail in Webmail they aren't deleted but appear strikethrough. Please read the the blog article (in German) how to remove them permanently.

Create new entries in the address book for each member of the planned group ("+ New contact"). Then select 1. the members (tick), click 2. on "to a contact list" (top right), select your address book there, click 3. then on "Add" and give 4. the list a name. Steps to create a group in Webmail address book

Probably "Norton Antivirus xxxx" or another anti-virus program is running on your computer, which wants to check outgoing e-mail. However, this virus checker does not understand encrypted transmission and returns this error (not the mail server). If you switch off the check of the outgoing mail, the encrypted transmission works.

You must download the e-mails from your still existing mail account. The best way to do this is with an e-mail programme, e.g. Mozilla Thunderbird:

  1. Downsload and install: www.thunderbird.net, Help
  2. Start and set up an e-mail account at TUC: Hints (in German)
  3. In the TU account you should see all your e-mails and folders.
  4. Create a new folder under Local Folders::
    Right-click on Local Folders → New Folder ..., name e.g. TU Chemnitz.
  5. Now you can copy folders from the TU account into this local folder: Click with the mouse, hold down and drag.
  6. Alternatively, select all emails of a folder in the overview – Ctrl+A. Click right → Move/Copy to … → Select local folder.

There are also tools that support a move, e.g. IMAPSize (Windows). With some webmail providers, you can use a function that allows you to retrieve the emails from the TU account and thus store them with the new provider, e.g. solution for Google Mail or Outlook.com or Outlook.de. Es gibt auch Werkzeuge, die einen Umzug unterstützen, z.B. IMAPSize (Windows). Bei manchen Webmail-Anbietern können Sie eine Funktion nutzen, mit der Sie die E-Mails vom TU-Konto abrufen und so beim neuen Anbieter speichern können, z.B. Lösung für Google Mail.

See also: Blog articles on e-mail (in German)