1. Make sure the email address really exists and is correctly formatted.
2. Ask the signatory to verify other mailboxes, such as spam, promotions, etc.
3. Ask the signatory to verify any filtering rules, blocked or insecure senders, and / or list order
4. Ask the signatory to verify the mailbox is not full.
5. Ask the signatory to verify any firewall or antivirus rules are  preventing  incoming emails
6. Ask the signatory if he/she has an Internet connection and the email client is syncing correctly.
7. If everything is correct and the client does not receive the email, cancel the request and start a new one (if possible, with another email).
8. If in doubt about the status, submit a support ticket to technical team (see “What information is necessary to submit a support ticket?”).