🥺Asking major mailbox providers for a reprieve

I've done everything right but I'm experiencing delivery issues on my IP addresses, what can I do?

Most large mailbox providers provide a method for bulk senders to apply to have their sending issues remediated.

When you pay a consultant for deliverability help, after they tell you the same thing you've read on the web hundreds of times in your life, they usually just go to these pages and request a pardon or at least a commutation.

Google's sender escalation form.

Yahoo's sender support request form.

Microsoft OLC support form for outlook.com/hotmail.com/msn.com/live.com.

You can also look into sender certification through Validity and see if it may be right for you.