Some days ago we (the skweez.net team) decided to try to replace all the fancy services from Google with software on our own server. So we looked at Roundcube for a decent web mail interface. Roundcube works great but we missed one feature: to send mails with a mail address from another email provider like Google. This is important as we wanted to use our own mail server to collect all the mails from all the different providers. Thats no problem with most of the mail providers but to answer the mails with the correct email address you need to send the mails through their mail server or your mail will be detected as spam.
Enter: The Roundcube Identity SMTP Plugin
This plugin allows you to specify a SMTP server for every identity you setup in Roundcube. You can now answer all the mails you get with the correct address from within Roundcube.
The plugin is available from github: https://github.com/elm/Roundcube-SMTP-per-Identity-Plugin It is not tested very widely but it works for us so it may work for you. Feel free to leave a comment or a patch or flattr this post.