WLM – some emails won’t open or show properties

I have two POP3 accounts.  All emails on account A open ok but 2 emails on account B will not open to display or to show their 'properties'

Following advice elsewhere on MS sites I did the following:

1. disabled MSSE (just in case)
2. restarted laptop
3. removed DSD (Dell System Detect ) using Control Panel
4. repaired WLM using Control Panel

Restarted pc after each operation but still no joy.

All the emails open normally on the same accounts set up in Thunderbird.

Any ideas, please