Best open source webmail clients


There are too many webmail clients are available on web.

Choosing best out of them is quit difficult task for any one.

After exploring tens of webmail clients, I will vote for following webmail client as top 3  webmail clients:

  • Roundcube: I would rate it as the best and easy to install. It has rich text editor and clent side filtering support. Also it hase good web interface.


  • Zimbra: Not explored much about, but based on futures its quite a popular webmail


  • SquirrelMail: Its basic webmail with basic web interface. There is no rich text editor support. There are lot of plugins available for SquirrelMail. 


  • RainLoop: Recently I seen this webmail client so thought to share. UI is good in RailLoop. I am not tested it but when I walk through installation procedure its looking straight forward and easy.
RainLoop WebMail

RainLoop WebMail

All above webmails are open source.

Roundcube SMTP Error (250): Authentication failed

Recently while trying to install roundcube I am stuck with the error “roundcube SMTP Error (250): Authentication failed”.

With the error the clear hint is there should be some issue with SMTP setting, so I checked all SMTP settings and I had bit doubt on following settings.

$rcmail_config['smtp_user'] = '%u';

$rcmail_config['smtp_pass'] = '%p';

After doing some experiments with my file following tweaks are worked for me.

$rcmail_config['smtp_user'] = '';

$rcmail_config['smtp_pass'] = '';