Email Web Form Application and concerns

[bgbs]

 

I run an interactive membership site where members post product ads and receive emails from interested parties. Members use my sites email form to write emails to each other.

 

When a member sends out an email using email form, the form uses a designated gmail address to deliver the message to the recipient.  The concern I have is, if the recipient decides to flag the email from the specific sender as spam, it would probably flag as spam the designated gmail address that is used to deliver the message, therefore any other buyer who writes to that seller would also be considered as spammer and never get emails from any member.

 

My question is, is there are solution to this  problem?