Hello Humans, thank you for the kind words. I hope the above advice helps, but it’s by no means a roadmap to 100% bulletproof warmup. It just depends on many factors.
I will talk about better inboxing and warmup at the Mauticon a little bit more, buy your tickets today 
I have to admit, I’m a little bit disappointed, that we are talking about warmup, instead of getting the last steps of the new email builder done that could catapult Mautic into the Leauge of Word Class Marketing Automation Software attracting more users and coders as well
MJML Grapesjs - Email Builder
I have a strong opinion about warmup services, and so called inboxing aids. I used them before, and I would like to lay out the pros and cons.
But before that you’ll have to eat your vegetables:
Not all IPs are created equal. There are the following categories (in my opinion):
1. Trashed
Someone purchased a 5 dollars VPS by a known service provider, sent out 10-100k emails via Postfix. At the tail of the send probably spamboxed 100%, and the IP was rendered uselss. Shows up as spam in any reputable spam filter. Our email marketer cancels the account and the trash IP is left for the next subscriber. Why would anyone do that? Because evil Youtubers and bad Udemy courses make you believe it is a sustainable business.
2. Mustang
This IP is just became available, noone ever misused it, in fact there was no email traffic on it yet. It is also possible, that this IP was just washed clean, and the reputation is zero. And by zero I mean you start from 5 emails / hour. Backside: like a free-roaming horse in the wild west, it needs to be tamed first. You need some skills for that, cowboy.
3. Nobility
If you go to Mailgun or Amazon (etc) and you are ready to pay for a dedicated IP, you will get one of this. It has some reputation already, you almost certainly don’t have to start from zero. These IPs are privileged, because these IPs are closely watched. Just because it’s yours only, doesn’t mean you can do anything with it. It’s like a rental car: you can’t crash them into the bridge. The provider will watch over their property. If you have good rep, thats good, noone else will affect your deliverability. The provider will check the reputation, but they don’t help you to keep it up. However, if you start spamming, you will be removed. The provider’s livelihood depends on good IPs and they are well connected with the ESPs, they actively request block removals. And the ESP will listen to them (see, privileged…) These IPs are not used by crash and burn warriors, because they are too expensive for that.
4. Shared IP
You can find small providers, who offer their SMTP and other bundled services. They can’t go in a price war with the big ones, so they try to throw some email verification, cleaning services for free at you as well. These IPs are usually good quality and the size of the provider allows to face-check the clients before they commit. They are a little bit more forgiving with affiliate content and ‘cold email outreach’.
5. Policed IP
If you sign up with Amazon (for example) you’ll be assigned to one of these IPs. They have 2-10 million emails running on these IPs every day, your send will be a drop in the ocean. There is a team of admins checking who impacts the reputation in a negative way, and they are immediately disciplined. This might sound like police state, and that is because it is. I can hear the knuckles cracking from anger, people screaming bad service and no respect for customers. But it’s really the only way to manage it properly.
If you are a good sender, it is a good thing for you. Policed IPs can help you to be among the best senders.
(Sorry, a bit longer than I expected, and in a minute I’ll answer your actual question )
Let’s go back to the ultimate goal:
You want to inbox (email delivered into the inbox, not promo or spam).
In order to do that, you need to deliver good traffic in a consistent frequency and amount. Forever.
It’s like with marriage: it’s not enough to bring flowers and wash the dishes during the courting period, you need to do that all your life. (Speaking a bit old school here, but you get the metaphor.)
So if you want to use the warmup services to skip the ‘being nice’ part, it is not worth it.
If you can be a perfect sender for the next 4 years, it should not be a problem to be a perfect sender for the first 4 weeks.
If you want to use warmup because you need to send NOW, and you are sure, that you’ll be a good sender after that as well, then this service can be a good solution. It happened to me too, that we had very good rep, but a stupid mistake ruined it all, and we needed to get a warm IP fast. Only use them if you are warming up a Mustang. Policed or Shared IP providers usually give you their own tools to warm up. You can also use this service if you send larger amount in a shorter time in the future.
Using someone’s warm IP is good if you know how not to mess up the reputation. A normal, good sender with double opt-in and non-scraped lists have nothing to fear. Go for it.
But if you think, you get a good IP and you can send your affiliate business through it, you are mistaken.
Using their SMTP with pre-warmed IPs. This sounds like a shared IP to me. So as long as they make sure noone else affects your send, and you are with good senders in the same pool, you are golden. I like to use services, that integrate with Mautic and ensure fast delivery.
I can’t cover everything here, but at the Mauticon I’ll show some email sending tactics, that are specific to Mautic and help you to keep your engagement up.
In the meanwhile, please bump up the Email builder topic