Problem in External domain mails

We are using lotus domino 8.5 server and Notes 7.0.3 Client. Our mail file template is Mail7.ntf. No issues in interanet mail. But user used reply with histry on any other domain mail (internet mail) it shows the time stamp when that mail received. For example we received a mail on 22-11-2009 14:30. We create a reply with history on today but it shows 22-11-2009 14:30 on that memo. What is the reason. Kindly help me.

Once again i inform you intranet mails have no problem. This problem comes only internet mails.