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Size of mailboxes and attachments

Mailbox size

All students have a maximum mailbox size (quota) of 2 GB via the student account.

Employees, on the other hand, have an unlimited mailbox size via the staff account.

Maximal size of attachements

When sending emails with attachments, the RRZK mail system only accepts emails where the size of the attachments (taken together with the mail itself) does not exceed around 35 MiB. Other mail providers may have stricter size limits (see below), so you can only be sure that emails of this size will reach the recipient when sent within the circle of users at the University of Cologne. This maximum size applies both when sending via the webmail system and when sending via an email programme such as Thunderbird or Outlook. It also applies in the same form when receiving e-mails.

Note on transport coding

When sending files by e-mail, they must be sent using so-called "transport coding". This increases the number of characters to be transmitted by about one third. If the e-mail becomes too large, the other person's mail server may reject your e-mail.

When sending to other providers

The provider of the destination address may limit the size of e-mails that can be received. If the file attachments are larger than the provider's specifications, your e-mail will be rejected. You can request the maximal size of attachments from your e-mail provider. Below you can find a list of the most popular e-mail providers (10/2022).

e-mail provider maximum size
Google 25 MB
GMX 20 MB 20 MB
Microsoft 25 MB
Yahoo 25 MB

Note: The limits you can find here, correlate with the free service of the e-mail provider.

Suggestions for folder size

Create folders and subfolders in your mailbox, to find messages easier and to make the filter work faster. You can adjust the criteria for the folders to your own requirements, like you can sort your mails in subfolders by dates or subjects. Also you have the possibilty to make own filter rules over the "Mailportal" to automatically sort mails in pre-defined folders.

To avoid problems in the usage of Webmail, we suggest to save not more than 10.000 mails in one folder (independently from the size of the folder). This helps to keep processes faster, like sorting messages.


Alternative ways for file transfer

You can send bigger files via Gigamove. With this service you can send and recieve files up to 2 GB.

There are also other services for a consistent transfer of files (like in work groups) at the University of Cologne. These services are set for different groups and can be individualised. When deciding which service to use, take in consideration wether you only want to share files with employees of the University of Cologne or also with external people.

If you have any questions or problems, please contact the RRZK-Helpdesk