How to handle email blackholing?

I am worried about outgoing emails getting blackholed because of tainted IP address provided by VPS. If my understanding is correct, blackholing sucks (no pun intended) because sender is not even aware that it is happening.

How can I handle this issue?

PS: why is this link broken: Join the Mail-in-a-Box Community Chat community on Slack!

Are you speaking in hypothetical terms or do you have an IP with bad reputation?

You can check up on your IP here:
If you are on blacklists you either need to invest time and effort to get off, get a new IP or get a VPS provider who dedicated to keeping their IP’s clean.

Even if you have a clean IP address, it doesn’t prevent an automated program from signing up using honeypot email addresses. This area seems riddled with anti-competitive strategies.

Besides, its naive to think that you can get “clean” IPs from cloud providers. Its near impossible. I wanted to set a transactional email server but it seems impossible to me because the IP will get banned, so big tech can make money.

Sorry, but it’s still not clear whether you expirence any specific issue or not?

Things like honeypots or email traps are mainly a problem for people who buy email addresses from dubious sources in order to send bulk emails. I think rightly so, because these people are responsible for making the email system the mess it is today, and you can call these meassures anti-competitive, but I’m of the opinion that there is no need for any more providers or participants in the email “marketing” space, and if you’re building a serious business, you don’t need this kind of advertising…

So, If you are looking for a guide on how to reliably send bulk email without getting in a spam trap, then this is probably not the right place to ask and MiaB is not the right product for you. However if you want to set up your own mail server for your family or a small business, then you’ve come to the right place, because that’s what Mail-in-aBox was made for for.

Good luck.

Why do you say mailinabox is not the right product for outgoing marketing emails? Its an SMTP server. There is no special bulk SMTP servers, its just SMTP servers.

Well, it wasn’t made with that in mind. But sure, it’s a mail server, so of course it can be used to send marketing emails. Also, if you send those marketing emails only to known recipients who have either subscribed to them or are known clients of your business, you won’t likely have any issues with email black holing.

But to answer your original question: No, Mail-in-a-Box has no built-in “magic sauce” to protect you from email black holes, honey pots or email traps, nor does it provide any specific tools that you might need to manage your spam marketing email lists. :wink:

my use case is sign up emails but i am worried people will use other people emails in efforts to lower my ip reputation. How do i handle that?

Who are you referring to with “people will use other people emails”. Who else would access your server. You can only send emails from an account if you have the correct credentials…

Its a sign up form where the user can enter their email to sign up. I am worried about people spamming by putting in irrelevant or honeypot email addresses that result in IP reputation drop. I need a way to handle this. One way I can think of is sending a link in the email that says “click here if you did not request to sign up”. But not sure how to handle the response from that link? Should I block email addresses being put in from certain IPs? If so, for how long? Is there a better way?

You will have to look into products like mail gun or AWS SES. Marketing email is a whole other beast than personal emails. You should look up best practices for these kinds of email, there are lots of tips and tricks that will improve deliverability, such as unsubscribe links, opt out links, etc.


I’ve setup Mailinabox for two businesses over the last 3 years using AWS with “clean” ip4s. Nevertheless, Microsoft ( and, Comcast and ATT rejected all emails. After struggling to get every little detail correct and filling all the forms, both these accounts are clear now. If you use AWS’s Lightsail, it is necessary to request from AWS the they set the reverse DNS in the server’s sub-domain.

Thank you. I was looking for someone like you. A few questions I will appreciate your perspective on:

  1. How did you verify that IPs were clean?
  2. Current, after filling all forms, you have 100% deliverability with your email?
  3. How do you handle email address verification to protect IP reputation?
  4. Can you share any other information that maybe useful for me?

When using AWS you need to add (at no charge) a static IP. There are a number of websites that can do searches to see if the IP # has been blacklisted. If it has, just drop that number and get another. Once you have an IP you wish to keep, then set the reverse DNS (or if using Lightsail, request AWS to set the reverse IP for you AND at the same time open port 25 for outgoing mail).
It take some real work to get Microsoft to unblock your IP. Be patients, read the white papers they recommend so you comply with their policies and be very persistent contacting them. Have not had any blocking since this was sorted; however, there is not a lot of mail going out from our servers. Certainly no mass marketing,
As to question #3, I’ve not had to worry about that as our users are confined to the businesses using the mail servers. I think that if you (or your users) are not spamming, there is not likely to be a problem. If you are doing mass mailing, it might be best to use a service that can provide this for you. They know how to send marketing without getting black listed.
Good luck!

Check reputation here.
It is unlikley that you will be able to send bulk email. You will get blacklisted very soon even with white papers and reverse dns and all that shajt. and google do not disclose their filters and often legit email ends up in their spam filters. Their anti-spam activities seem very hidden so people would not start setting up smtp servers as well as email busnesess to profot from that. Your reputation might look clean to you, but it can change overnight. Good luck

For sign up emails DO NOT use your Mailinabox YOUR CLOUD port 25 ip. You will get blacklisted. Use, as stated in the comments, the AWS or OCI cloud marketing relays. Or maliljet. AWS has 1000 free messages and OCI has 2,500 in the free-tier. OCI, if you enlist for PAY as you go, will let you send 1000 per month for free. Mailjet has 15000 per month, but it sucks as they themselves filter. There are a buch of others but they do filtering themsleves and some of the messages end up unsent. Avoid free bring your own domain sucj as ZOHO as it has the dirtiest IPs. Just validate your domain (AWS or OCI), and you can use both. The signup info email should go via AWS or OCI or similar, smtp relays. Only then you can use your regular Mailinabox email via your port 25 Mailinabox and expect delivrability. FIRST delist yoursef from the blacklists before you attempt anything. It is a slow and painful process.
NEVER USE Mailinabox as an smtp relay for websites you manage such as Wordpress Joomla or similar beacuse you will get blacklisted. Otherwise be very careful and inspect the system messages you send out. There are html checkers and unsuscribe butons well documented but even that is not a gurantee.

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