HOW TO USE GMAIL WITH OLD CLIENTS

No, I don’t mean with your customers that are old, I mean with email clients like Outlook Express and Outlook 2003. You’ll most likely get the error: “[AUTH] Web login required: https://support.google.com/mail/bin/answer.py?answer=78754”. What you absolutely have to do is set “Less secure apps” in the domain management area, Security, Advanced security settings:

less_secure