Situation: 
Our Auction Client is sending promotional emails. However, a particular recipient is not receiving them, the recipient is not disabled, is on the mailing lists, and has received the emails in the past.

Solution:
Ensure the email client on the recipient has the emailer domain safe-listed within their email software, ensure the domain @autoremarketers @awgremarketing is also safe-listed. Next check the clients, the email recipient, anti-virus is not blocking email from the safe-listed address.  This could be any and all anti-virus software as they have built in mail scanners and blockers.

Other Possible solutions:
1: ISP (Internet Service Provider) is blocking bulk emails and/or emails from the particular sender(s). Client will need to call their ISP to resolve this.
2: The email Service provider has particular domains and/or IP addressesblocked from passing email through. Client will need to call their Email Provider to ensure the senders domain is whitelisted along with, @autoremarketers.com @awgremarketing.com and SMTP.Sendgrid.net are all whitelisted.