Problem Definition:

You are unable to send email messages via SMTP (TCP Port 25) from a CloudConnect desktop host or server application.  The connection times out.  Hosted email services (Microsoft Exchange, Gmail, IMAP accounts, etc.) are not affected.


CloudConnect blocks SMTP (TCP port 25) outbound as part of its Internet Security/Acceptable Use Policy.  This is to prevent CloudConnect IP Addresses from sending uncontrolled email messages, which can result in a blacklisted address space.


Route email communication through a smart host or a hosted SMTP relay.  SMTP relays may be purchased inexpensively from third party email hosting providers.  The SMTP relay should listen on a nonstandard SMTP port, and will relay the email to the appropriate address.

Additional Information:

For more information on CloudConnect’s Internet Acceptable Use Policy, please visit

Applies To:

Citrix XenApp 6.5

Microsoft Windows