Comment # 6 on bug 1011127 from GuoQing Jiang

/var/spool/mail is a symbolic link to /var/mail (it is same in most distros
like arch, RH and Debian etc.), it was used for mail delivery daemon I think,
so it means we should not use the /var/mail as a mount point. And I can't set
/var/mail mount point when I install os, yast would complain about "var/mail:
Cannot create symlink to 'spool/mail': File exist".

I guess you set /var/mail mount point after system is ready, and after update
system, yast will be confused about the mount point since it is a existed link
to /var/spool/mail. In short, I'd suggest not to set /var/mail as mount point,
thanks.