Why we block these Attachments?

As part of our commitment to keeping our customers secure online from viruses and other harmful software. Zen has restrictions on certain email attachments being sent and received through our servers.

These restrictions are in line with other email providers and ensure we are following industry best practice.

Our Scans and what they block

We always scan emails for potentially malicious content such as viruses and malware. These scans are carried out mainly on attachments, but also the body of the message itself (e.g filtering emails with links to phishing or malware sites).

Our signatures are provided by external providers who are always willing to take false positive reports if a rule falsely flags a message body as malicious the rejected message's bounce-back will detail how to report this to us.

Office Documents (.doc, .docm, .xlsm etc) with detected malicious OLE Macros will not be allowed through our mail servers.

Restricted File Extensions

Certain file types, either attached or found within an archive (Zip, Tarball, RAR) are not allowed through our mail servers.

False positive reports for these file types won't be accepted by Zen and any files with these extensions will instead need to be sent using an alternative method such as a cloud storage or file sharing.

Below is a list of all the file types we do not allow through our mail servers: