there is a setting in the webmail and squirrel mail to configure the recipient to reply your email to other account. This is use when you don’t want the recipient to reply to your inbox instead reply the email you have send to him to other mailbox (e.g firstname.lastname@example.org)
1.) Open and login your webmail / squirrelmail and click Options
2.) Select Personal Information
3.) Under the Name and Address Options, replace the Reply-to section with other email or empty it to default setting.