sendmail[23933]: [ID 702911 mail.warning] STARTTLS: write error=syscall error (-1), errno=32, get_er

 I'm seeing the following message on /var/adm/messages:
sendmail[23933]: [ID 702911 mail.warning] STARTTLS: write error=syscall error (-1), errno=32, get_error=error:00000000:lib(0):func(0):reason(0), retry=99, ssl_err=5

It appears several times throughout the day on most (but not all) of my 20+ severs.

Any ideas where I should look?

Thanks
GlenG