How to check whether the mail is read or not

- How to check whether the mail is read or not in outlook
- How to check whether the sent mail is read or not
- How to check whether sent mail is read or not in outlook
- Can we check whether the mail is read or not in outlook
- How to know whether email is read or not
- How to know if an email has been read
- How to check email address is valid or not
- Email read receipt outlook
- How to check if an email address exists