I used to be able to go to Accounts and Import → Add another email address you own and add an email account that's only a forwarding address. That is, it's not a mailbox and I don't have SMTP access to it.
Gmail would send me a confirmation email to that address, I'd confirm it's mine, and done. Now it only gives me the option to add SMTP credentials.
Did they stop supporting the previous method? Is there any other way I can get that option back?
Best Answer
Gmail recently changed its policy. Now it does not permit anymore to use the Gmail SMTP server to send email on behalf of another domain. This is to avoid spammers and enforce some security policy.
So, if you have an address aaa@bbb.com you also must have an SMTP server for bbb.com (e.g. smtp.bbb.com) and an account on that SMTP server. If you have those, you can enter that information in Gmail and set up that account as an alias.
Essentially, Gmail becomes just a client for that address, using the address’ SMTP server instead of Gmail SMTP server, to send mail for that address.
You can continue to use the Gmail SMTP server to send mail only for other Gmail addresses, or for Google Apps addresses.
References:
Support page, originally posted here
Unofficial Google OS blog post