When the Sender of a mass email is set to Account manager, each email is sent from the account manager of the recipient's company. A company can have two or more account managers when Enable multiple account managers is turned on under Settings → Account → Account settings. In that case, the email is sent from the one with the lowest user ID, which is the one who was created first as a user in Upsales. The sender name and the sender address both come from that same user.

If your account uses brands and the brand the email is sent from is limited to certain roles, account managers outside those roles are skipped and the email is sent from the remaining account manager with the lowest user ID.

If the company has no account manager, the email is sent from the default sender of your mail account.

When you choose Account manager as sender, Upsales checks the email domains of all active users, not only the account managers of your recipients. If any of those domains is not verified, the sender shows a warning that lists them. Verify the domain as described in How to add an email domain, or correct the user's email address.

To send from an address that does not belong to any of your users, see Q: How do we add another sender address to our email campaign?