Outlook.com / Hotmail.com Blocking Email

The misleading wording from Sendgrid made me think it was my IP that was the problem. It is theirs as I now know, and they tell me that can happen if you are on the free package. Can't really argue as its free, but it's not a great way to trial something.

I thought the free trial was going to give me an idea of how good they are before going for the paid account, where (they say) you get a dedicated own IP so it won't get blacklisted due to someone else.
Now I have an issue with Amazon.

Been using fine for a few weeks, now suddenly btinternet is blacklisting. It affects only forum notifications though, a test email sent via same SES account on my computer with mac mail is fine.

This is the fail message:

Diagnostic-Code: smtp; 554 Message rejected for policy reasons (
Last I heard you were using Amazon IIRC, are you getting the same thing with BT?

I am wondering why it is fine when sending via mac mail, but not zenforo notifications.
I don't have any customers with a BT address.
Just testing mailgun on cafesaxophone to see if I get better luck in regard to btinternet and AOL bounces. Documentation seems to be written for devs rather than dummies (which is to be expected) but seems so far seems to be OK.
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All of a sudden Mailgun IP seems to be blacklisted:

Server response: 522 email sent from found on industry IP blacklists on 2018/02/26 22:40:10 GMT, please contact your mail sending service or use an alternate email service to send your email. Guide for bulk senders www.bt.com/bulksender
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Honestly, mail is a nightmare. After doing this for several years now, I'd rather see mail notifications go out via a push method than relying on emails for alerts.
Honestly, mail is a nightmare.

Tell me about it, as you know I've been though Mandrill, Sparkpost, Sendgrid, Pepipost, Amazon and now Mailgun. I think part of the problem is of course companies like BT and AOL being too eager to aggressively block stuff, or whoever it is makes up the blacklists. Looking like Amazon SES may be the least worse, but they still get blacklisted sometimes. Actually I think Mandrill were good, but then switched to only being available if you had a Mailchimp subscription.
Dedicated IP's with mail providers are the best bet, I've got a problem with a clients email at the moment where Outlook have blocked their hosts IP ( shared host ) and sendgrids shared IP.

The days of getting mail delivery for free are long gone imo, Like you said mandrill was good, but it also wasnt sustainable to offer for free. I suspect sendgrid, sparkpost etc will all eventually follow suit as their free services get pounded more and more taking their resources and time to resolve issues.

I reported the IP blocks to sendgrid 5 days ago, they are still blocked on my clients account......................but strangely work on mine which although is a paid account its not a dedicated IP account
mailgun seems to be getting worse with more and more frequent blacklisting and slow to fix it. To get over current problmes at a very crucial time for one of my forums I have upgraded to dedicated IP but cannot afford to continue with that

Postmark looks good might give them a go
It's getting worse everywhere. I'm seeing Amazon SES having their shared IP's added to black lists as well. People seem to think it's OK to just mark something as SPAM now if they don't want to receive it, rather than unsubscribing properly.