Server-side Attachment Management

Global e-mail attachment settings allow you to specify global rules for handling attachments of an e-mail message.

Modify list of blocked file extensions

You can set rules at COS-level and also for individual accounts. When attachment settings are configured in Global Settings, the global rule takes precedence over COS and Account settings.

A list of formats (extensions) can be created via CLI to restrict the attachments allowed.

Warning

All files whose extension is in the list will never reach the recipient.

For example, to block .exe filex, use command

# carbonio prov mcf +zimbraMtaBlockedExtension "exe"

Hint

Only one format/extension at a time can be specified.

Manage attachments’ size

It is possible to limit both the size of a message and its attachment and their individual sizes.

The total size of the message can be set for each MTA server directly on the Carbonio Admin Panel, in the Tuning section under Admin Panel ‣ MTA ‣ Advanced (see documentation).

The maximum size of each attachment can be set by the CLI for each user, CoS, or domain issuing as the zextras user

zextras$ carbonio prov ma alice@example.com zimbraFileUploadMaxSizePerFile 1048574

This command prevents Alice to sent an attachment larger that 10Mb.