FAIL (the browser should render some flash content, not this).


Q: What is the maximum e-mail attachment size?

A: The e-mail servers do not limit the size of individual e-mail attachments. The e-mail servers do impose a 400 MB maximum total message size limit. Our Hosted Exchange and Kerio Hosted E-Mail services have a 50 MB maximum message size limit. Individual customers can choose a smaller message size limit. We can also customize the handling of "over-sized" e-mails. Please contact us to discuss your specific needs. A couple of important facts:

  1. Attachments are typically encoded in what is called Base64[1]. As a result, the actual length of MIME-compliant Base64-encoded binary data is usually about 137% of the original file size.
  2. E-mails often contain both plain text and HTML components. This also increases the overall size of the e-mail.


Q: If my personal computer crashes, will I lose all of my email?

A: The short answer: it depends. The long answer: If you are currently using POP3 retrieve (and remove) your e-mail from the server, then yes. This is because the e-mails are only stored on your server. There are at least two ways we can help to resolve this problem:

  1. Configure your e-mail client to connect to the servers using IMAP instead of POP3. With IMAP your e-mail is stored primarily on the server and your e-mail client may only be storing a copy of your e-mails. Many modern e-mail clients (like Thunderbird 3.x) employ synchronization techniques to improve the performance of IMAP. This enables virtually all of the same functionality as POP3 along with keeping a copy of your e-mails on the server.
  2. Subscribe to our E-Mail Archiving Service. With E-Mail Archiving Service, a copy of every e-mail you receive (and send) is archived to a separate server. For more information, please see this page or contact us to discuss your specific needs.


Q: Is there more I can do to protect myself from identity theft or spyware online?

A: Yes, there are quite a few things that you can do that will help. Here is a sampling of helpful items:

  1. Education - the more you know, the better you can protect yourself. Here are some resources that you may find useful:
  2. Do not reply to spammers, for any reason - Replying to a spammer only confirms to the spammer that your e-mail address is valid and your e-mail is read by a real person. This increases the value of your e-mail address to the spammer and will most likely result in more spam being sent to your e-mail address. In the event that you receive an e-mail that should have been classified by our system as spam, please see: HOWTO - Send SPAM samples to ETRN for our recommendations.
  3. Use the safest web browser that you can. For example, a tool like Secunia PSI ( can be used to help determine the security of your installed web browsers. Any browser listed as "Not secure for browsing" should not be used for general web browsing.


Q: Why postmaster@domain.tld? Why not a different e-mail address?

A: We use the postmaster e-mail address because the postmaster@ e-mail address is the only required e-mail address in your domain.. This requirement is detailed in RFC5321 Section 4.5.1.


For more answers to your questions, please visit our support page