I am using an smtp server which requires authentication. The issue is that the username must be provided in the form of domain/user. I have this in my .muttrc: set smtp_url = "smtp://domain/user@xxxxxxxxxxxxxxxxxx:587/" set smtp_pass = "xxxx" When I try sending an email through Mutt this is what I get: Could not find the host "domain" What's happening here? What's the correct syntax for this? Thanks, Luca.