Requesting SMTP Relaying for sending unauthenticated email

An SMTP relay is used for sending unauthenticated email. SMTP relaying is necessary when you need to send email programmatically to recipients that are off-campus and the list of recipients may not be known before the email is generated. To submit a request, fill out the form below.

What is SMTP Relay?

An SMTP relay allows Campus users to programmatically send mail from their applications to their target users without having to run their own mail server. Common uses range from servers that may generate high volumes of mail to low volume printers, scanners and multifunction devices. This service can be used where a smart-host is required. This can be used to send mail to both campus and non-campus mail addresses. This service is insulated from spammers by maintaining a table of IPs allowed to relay.

Office 365 / WiscMail / WiscMail Plus customers may not need an SMTP relay in all cases. If you are a WiscMail Plus administrator, please see the following guide to help determine what option is best for your needs: Office 365 - Options for Individual and Programmatic Sending

Submitting a Request

To submit a request for a new SMTP relay or to change an existing SMTP relay, fill out SMTP Relaying request form.

Set Up

Once your IP is allowed to relay, you may use the following configuration to relay email.

  • SMTP Server: or
  • SMTP Port: 25
  • Id/Password: This is not used. Please leave blank.
  • TLS/SSL: This is not used.

Important: You must enter a valid From address. This address can be a or account that is hosted within the UW-Madison Office 365 tenant.

What is the difference between and

Both and will allow you to relay mail if your IP is listed in the WiscMail Relay table. is a newer service, which is set up to emit traffic on an alternate set of IPs separate from the traffic being sent by end-user accounts. The reputation of the email traffic relaying through will be better, which should result in a higher likelihood of messages arriving in Inboxes of the remote email services. Unlike the IP address of the device sending email must be included in the WiscMail Relay table in order to use This is true even if the email is being sent exclusively to O365/WiscList addresses


If you have any questions or would like to discuss relaying options, please contact

See Also:

Keywords:wiscmail plus campus relaying smtp requests sending email programmatically e-mail allowing whitelist o365 office microsoft   Doc ID:29362
Owner:Ara M.Group:Office 365
Created:2013-04-08 14:50 CDTUpdated:2017-06-08 13:24 CDT
Sites:DoIT Help Desk, DoIT Staff, DoIT Tech Store, Office 365
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