Skaero,thank you very much.
gmail have this Function....
Send mail as:--------------------------------------------------------------------------------------in gmail Accounts and Import
(Use Gmail to send from your other email addresses)
Check mail from other accounts (using POP3):
Learn more
Add a POP3 mail account you own
Add another account
can my roundcube connect other smtp to send mail?
How should I do?Which plug can be used?Or edit which configuration file?