1. Login to pleskCP
2. click on domain.
3. Click on domainname.
4. Click on dns settings.
There select following 3 records mail.domain.com A records, webmail.domain.com A/CNAME records & domain.com MX records.
5. Click on Remove.
It will ask for the confirmation select the confirmation box and click OK.
6. Click on add records
   > Record Type : CNAME
   > Enter domain name : mail
   >Enter a canonical name : ghs.google.com (Click OK)
7. Click again on Add Record
   > Record Type: MX
   > Enter domain name : leave it blank
   > Enter mail exchanger : ass the google has update you the MX records
   > Specify priority of mail exchange server. : set the priority as google updated (click OK)
8. follow the 7th steps and add all the MX records which google has updated you.

Note : If you face any issue please raise a ticket from client/member area.