Hello,
Thank you for your question. Since this is just our public forum, and we have no way of identifying your account, it makes troubleshooting difficult at best.
Since there are many reaasons an email can be delayed, each email failure must be handled on a case-by-case basis. If the email was returned our Bounceback Parser tool can help provide more information.
Please provide the full failed email with the returned/delayed message error, so we can investigate further.
If you prefer to provide this information in a secure (non-public) setting, please forward the returned email to Live Tech Support in a ticket.
If you have any further questions, feel free to post them below.
Thank you,
-John-Paul