TestComplete - Sendmail using CDO object do not work when the email address contain uppercase letter

When the email address contain the uppercase letters it do no work 

 

For e.g. Ryan.Reynolds@ttu.edu is the email address- in the email address the first letter R is in uppercase. 

When we use the same email address in our testcomplete it do not send the email.

 

We are here using Outlook which is part of office365

 

If the email address contain all lowercase letter then it work.

 

Any idea why it happens ?

 

Thanks

NG