If you are receiving complaints that system generated emails are not being received such as high bidder notifications, invoices, etc, please advise the bidder to check their junk/spam folder first, and if the email is still not present, they need to add your site to their safe senders list. Some email providers have filters in place that will immediately block an email so that it isn't present in a junk/spam folder, so additional steps will need to be completed by the bidder to ensure that such filtering is disabled.
Instructions on how to add a safe sender and/or ensure proper spam filtering is in place for nearly all mail providers can be found here: https://www.whitelist.guide/
Please note that most of these steps must be completed in the webmail version of their email, not within a program like Outlook. The guide above will point out this step if that is true. For example, if I have a @cox.net email address and check my email via the mail app on my phone, I cannot simply mark the sender as safe from the email program on my phone. I have to login to my cox.net webmail program and make adjustments there.
This site will also provide information on steps that you can take to ensure optimal deliverability. For example, if you notice that only @gmail.com emails are not receiving emails from your site, the guide for Gmail includes their Postmaster Tools (https://www.whitelist.guide/gmail/). Most email providers will have their own postmaster site that will provide assistance on ensuring emails are delivered.
For additional resources on how to restore sender reputation and reduce the amount of spam email delivered, please see: https://glockapps.com/tutorials/restore-sender-reputation/ and the Google Postmaster tools found here: https://support.google.com/mail/answer/9981691?visit_id=637848769211487090-1243198458&rd=1
Changing certain DNS records as explained here can also be helpful: https://glockapps.com/tutorials/improving-email-deliverability-using-mx-spf-ptr-records/
If you need assistance with DNS record changes, please contact support@simpleauctionsite.com.. The most common change needed is the addition of ip4:40.76.237.188 to your existing TXT/SPF DNS record.
If you receive a mail failure/bounce back email, please forward the email contents to support@simpleauctionsite.com so that we can determine the source of the failure.