If a customer reported that the email is not received on their end, please check the following items below to determine the cause:

First, have the customer check their Spam or Junk Folder. It may be delivered there especially if you haven't set up your DKIM yet. Also, have their local IT check and ensure that NetSuite and your company domain email are not blocked.

You may also check all the undelivered emails filtered from your server to see their correspond failure reasons by navigating on Lists > Mailing > Undelivered Emails.

If not resolved, please check the following areas below to ensure that the issue is not being caused on your end:

1. Navigate to Lists > Relationships > Bounced Email Addresses. Ensure that the recipient's email address is not listed on the list. If listed, just select then delete it. Try to send the email again.
2. Open up the record you sent it from, then under Communication tab, the email should be listed there. Try to resend and if fails to deliver again, it could be an issue on your end.
3. Navigate on Setup > Company > Communication > Sent Email List, the email should have a YES status under SENT column, if NO, then check the detail of the error to sort out.
4. Lastly, ensure that your DKIM is set up correctly. This is to avoid sending the email straight to your customer's spam or junk folders. This helps validating your domain address. Navigate to Setup > Company > Email > Email Preferences. On the Domain Keys subtab, click the active domain selector then hit the Verify DNS Entry button. It should be verified, if not, fix the DKIM.

NOTE:

You may visit this link for the most common error and how to fix it: Error: "There are errors in your DNS entry for DKIM. Error: missing required entry [k=rsa]"

To know how to set up your DKIM, visit this link: Domain Keys Identified Mail (DKIM) Setup