Alias Emails and Send as Addresses
If you have set up alias emails in Microsoft Admin Center, you can enable them in BulkSignature as well. If you want to know what aliases are and how to use them, refer to this article.
How to enable Email Aliases in BulkSignature?
Enable the feature:
Go to Settings > General Settings.
Locate Email Alias.
Click on the toggle to enable the feature.
After enabling the feature, go to Company Data.
Click Import Now.
How to View Alias Users?
Once you enable the feature and hit Import Now, you will see email aliases in the same list as your regular Microsoft 365 users. Alias emails behave the same way as your regular users. You may define their names, job titles, custom fields, and more. You'll be able to see them tagged as Alias next to the user names.

