[Warning] Aborted connection 155 to db on Postfix Mail Server

Hi,
i have problem with my cwp server.
I think this is the reason why i can't send or receive any email.
This massage appear on Postfix Mail Server:

[Warning] Aborted connection 155 to db: 'root_cwp' user: 'root' host: 'localhost' (Got an error reading communication packets)
[Warning] Aborted connection 154 to db: 'postfix_policyd' user: 'root' host: 'localhost' (Got an error reading communication packets)
[Warning] Aborted connection 153 to db: 'postfix' user: 'postfix' host: 'localhost' (Got an error reading communication packets)

How to solve this problem?
Thank you for your respon