Mail file lost...?

[Dallas]

I've got a problem that has stumped me. . .I do some comsulting
work for a company that runs an Altos 2086 system, and one
person on the system has lost his mail twice in about 6
weeks.  His mail file, when I look at it, just has a bunch
of ^@ all over the place. . .Has anyone ever seen this before?
Is it a documented bug in the Altos Xenix?

        Thanks,
           Robert

P.S. On the same subject, does anyone have a pd version of mailx
     for an Altos?  Mail needs help severely!