SSRS Error: Failure sending mail: The specified string is not in the form required for an e-mail address.Mail will not be resent.

SSRS Error:

Getting the following error when trying to setup SSRS subscription…

Failure sending mail: The specified string is not in the form required for an e-mail address. Mail will not be resent.

Issue:

If you are using an SMTP server or forwarder that uses e-mail accounts that are different from the domain user account, the report delivery will fail when the SMTP server tries to deliver the report to that user.

Also make sure you have an valid sender address email value in the SMTP Settings section of Report Server Configuration Manager.

Fix:

Go to Report Server Configuration Manager -> E-mail Settings

Make sure the “Sender Address” field in the SMTP Settings is set to an email address.

Referenece:

https://learn.microsoft.com/en-us/answers/questions/874875/ssrs-email-error-failure-sending-mail-the-specifie

https://learn.microsoft.com/en-us/sql/reporting-services/install-windows/e-mail-settings-reporting-services-native-mode-configuration-manager?view=sql-server-ver16#configuration-options-for-setting-the-to-field-in-a-message