One of the biggest problems with using Gmail with a custom domain email account was that you could send mail from Gmail as you@customdomain.com without recipients seeing the nasty little “From username@gmail.com On Behalf of you@customdomain.com” message with every email. The reason for doing this was to help your email avoid being caught in spam folders and to show the recipient’s mail server that “Hey I know i’m not using my customdomain.com SMTP server but I still want to pretend this message is coming from you@customdomain.com”
Well the Gmail team has finally opened up the option for you to use your customdomain.com SMTP server for sending mail. If your you@customdomain.com email address doesn’t have a SMTP server for you to send through, you can still send it the way that Gmail used to handle it with the “On behalf of…” message.
Here is the announcement from the The Official Gmail Blog.
