Hi Ravi , you don't have to change processes if you have not hardcoded any of these server names. Changing Mail Server attribute is enough in both environments

Agree, it should be fine just changing the environment fields in workspace -> Mail server connection string to the new server. vernon

Just changing the environment field doesn't change the smtp server name that the event bus uses to send automatic notificaitons (from what I've seen).  I think you will need to modify a few config files as well for the event bus.  Take a look at:

http://www.k2underground.com/forums/p/11668/34298.aspx#34298

@rpichaimani I think all required steps for email configuration changes in current versions of K2 can be found in this community KB:

http://community.k2.com/t5/K2-blackpearl/There-is-no-connection-string-for-the-destination-email-address/ta-p/80086

Email configuration is externalized from process and K2 server relies on connection strings in configuration file, processes look at Environment Library, but you should also keep in mind String Table. I saw cases when people did update of Mail Server field in environment library, but their workflow was deployed from other environment with old/incorrect email settings which were written into String Table during deployment time - so you should also make sure that you have correct settings there.

An easier way will be to re-run the setup manager and change the configuration, so that the backends is being updated.

HTH. 

@Juliana Yes Setup Manager is easier especially if you know that you have to use Reconfigure for this (I seen people erroneusly trying to use Repair option just to change configuration setting), but as for now you can not configure authenticated SMTP connection through setup manager - it does not expose any fields where you can enter User Name and Password for SMTP.