You need an email deliverability specialist or a backend developer with expertise in email server management. Your issue is related to IP reputation and rate limiting, which suggests your email-sending IP has been flagged, possibly due to spam-like behavior or a misconfiguration.
Who Can Fix This?
Email Deliverability Specialist – They handle email reputation, authentication (SPF, DKIM, DMARC), and IP warming.
Backend Developer – If your system needs code-level fixes related to email handling.
SysAdmin / DevOps Engineer – If the issue is related to your server or hosting provider.
Where to Find Trusted Experts?
Upwork (upwork.com) – Find vetted freelancers with reviews.
It’s not about development; it’s about managing your own mail server, which is not trivial because of spam prevention measures everywhere. A system administrator should deal with it. Basically, you need to check blacklists and ask for removal if blacklisted. And ensure that no spam is going out.
@Gray
Right, the only concern I have is that although I know who hosts my site, I can’t quite figure out who hosts the mailing service. I am really stuck here in how to find this out?
This is a brilliant tool I use to test deliverability. Give it a whirl.
Thank you, I got a score of 8.9/10. Everything was a tick except for the spamassassin giving -1.1. When I clicked into that one, it shows -1.985 for PYZOR_CHECK. No idea what that means ;/
Jordan said: @Davi
Was your test email blank? That tends to flag up with empty emails.
Yep redid the test and got a score of 10/10 this time. This did come up in the spamassassin which is what I got in the previous test too -1.284 RCVD_IN_RP_RNBL but has a green tick overall.
This is a kind of mixed bag. A backend developer could help with this, but a frontend dev could easily do this as well. Just depends a bit on the infrastructure.
But the basics are that you need to use a different server or better yet pay for an email provider that has a reputation you can leverage. I use SendGrid; it’s got great APIs for sending emails. But basically, your custom SMTP server is coming up as spam and servers don’t want to send the emails that are coming from it.
You better look for mailing services like SendGrid, Mailchimp, etc., for email sending. Self-host mail servers are pretty much dead these days. Reason? The public IP you use has a known history of spamming or is suspicious about spamming.
@Zen
I see, well say I did go for one of those mailing services you listed. Would that require me to manually configure the change on my end so that the emails are going through Mailchimp, for example? Reason I ask is because I don’t have any programming knowledge and would have to find someone.
@Davi
Yeah, you will need to find someone. But if your site is built with WordPress or any other CMS, there is a good chance they have a plugin for this; then you can just install it, give it your Mailchimp details, and it can then start sending out emails right away. But better that you consult someone for this who can work with that.
@Zen
Unless you’re paying for a dedicated IP through those services, you’ll be using a shared IP, which means you run the risk of it being flagged as spam due to how others in your pool are behaving.
Self-hosted email servers are far from dead and are the most reliable way to go, but they’re more costly. Just because you’re using an IP that was in use before doesn’t mean it was abused, and reputation can easily be rebuilt.
Email delivery standards have been evolving over the years. You may need to update your setup.
Specifically:
Only use authenticated connections to send emails - avoid relays.
Avoid sending from email addresses you don’t control (the From header). Send “From” an address you directly control and use the “Reply-To” header if you want replies to go elsewhere.
Ensure you’ve implemented SPF.
If you implement DKIM, ensure that the automatically generated messages pass.
Ensure that all the email addresses you try to send to are up-to-date and valid - if any bounce (repeatedly) or recipients mark the messages as junk, this can affect your IP reputation.
If possible, provide the option to opt-out (using the List-Unsubscribe header).
Ensure the message clearly states where it came from and why the recipient received it.
Check recipients are only receiving the intended number of notifications (e.g., there’s no bugs causing the same notification to be sent repeatedly).
As others have mentioned, online tools such as mail-tester.com can help you spot and resolve (potential) issues. Fix as many issues as you can.
Your email hosting provider may be able to provide additional assistance (it looks like SpamExperts is involved in the chain, but they may not be your provider directly).
(I’m not sure why OP is being advised to change provider / stop using self-hosted, when as far as I can see from the information provided, all the servers/IPs involved/mentioned are from well-known email service(-related) providers).
You may need a backend developer to let you know how the application is sending emails (e.g., is it using authenticated SMTP connections?) and check if there are any issues that may be causing more emails than intended to be sent. Your email provider should be able to help you check your email setup (specifically with regards to DNS settings) is up-to-date.