Hi Lakjin --
You asked about Process Control (PCTNL) and in-housing an ESP/reputation, etc....
When I first setup MailWizz, from everything I read in the forums I expected PCNTL to be an optional module, but so far, on 3 different servers across 2 different hosting companies, it's been installed by default, so maybe it's becoming more common. I figured it's kinda like cURL - I've never worked on a server that DIDN'T have cURL pre-installed, but every guide I read online makes it sound like it's rarely available...
For in-housing your ESP: there are a lot of components to this - so instead of asking "should I do it", it's better to ask "how much of this do I want to own?" The next question is "do I have special needs that can't be serviced by MailChimp, etc?".
So why MailWizz (or why did I start with Interspire IEM back in the day)?
First: Cost! The MailChimp's of the world aren't stupid: they get you in the door at a low bargain rate, and as your business grows so does your sending cost. They charge you per message, which can add up to tens of thousands of dollars for a larger company. If you own the infrastructure yourself, you can send as many messages as your system & IPs can handle for a flat-rate. For our system, we pay about $2,000 a month right now, flat-rate.
Second: Control. Let's say you're on InfusionSoft. You upload a list of 10,000 clients from a conference you held because you want to send them all a thank you. The first thing that happens is that InfusionSoft makes you fill out a 20-field form to ensure you're in line with their spam policies. THEN, after you write the message, InfusionSoft sends the first 500 copies, waits to measure spam complaints, and if you have more than 4 it stops sending entirely. That actually happened to us 3 days ago with InfusionSoft, which is why we do all our bulk-sending through MailWizz. It happened to us about a year ago when we tried the same thing on Amazon SES too.
So the issue of control comes down to this: back in the day, when CAN-SPAM went into effect, ESP's started freaking out, so they put in policies that went WAY above & beyond the actual legal requirements of the CAN-SPAM act. Next thing you know, sending an email requires a double-opt in process, and if you have more than X number of complaints, they turn your account off entirely.
Another aspect of control comes down to keeping your system clean: the MailChimps of the world make it more difficult to keep a clean list than I prefer. In fact, in my case, I literally store my lists outside of MailWizz, and periodically I'll update them with opts & bounces - then I'll literally blow away MailWizz entirely & do a fresh install & reload from scratch. Keeps the DB clean & runs faster, and it's easier than trying to shuffle hundreds of thousands of leads around somebody's web-interface.
OK, now: more on speed. I addressed our system specs above, folks have asked how we achieved that. Let me elaborate a little more on what I've seen now that I've got 5 months in with MailWizz.
First: You REALLY want to have 16 gigs of RAM installed on your server. We've run MailWizz on machines with 4, 8, 16, and 32 gigs installed, and it DOES make a speed difference. I had page-loading issues on the 8-gig server, but when we bumped it up to 16 that went away entirely. The reason is mostly because using PCNTL runs multiple processes, and they all have their own RAM requirements - we will run up to 20 or 30 of those simultaneously for super-fast sends, but it eats RAM. Our servers are all using 2.2ghz XEON processors, too - those seem to make a difference, but a bit less so. Stop & think about it for a second - all the operations that you have do in order to send even a single email message. Yes, they're only tiny text operations in PHP, but they add up.
Second: You REALLY want a local database. If you can't do this, at least make sure your database isn't in another data-center. That makes a tremendous difference. Obviously this ALSO eats RAM, but at the same time, when you think about all the queries that are involved here, it just makes sense that you don't want to be shipping those across the country over & over again.
Third: You REALLY want a fast SMTP relay. The way to tell is this is an issue is that past a certain send-speed with MailWizz, you'll start seeing delivery errors (actually, looks like that feature has been removed - I'll have to ask if it's going to be put back in). If you're on a big corporate email relay, then maybe this isn't an issue, but if you're hosting through a smaller outfit, you want to keep an eye on your delivery rate to ensure that your relay is actually catching all the messages that MailWizz sends it. In other words, once you get MailWizz to send hundreds of thousands of messages an hour, the bottleneck shifts from your server to the relay actually sending them.
That's as far up the pipeline as I manage things in our operation. If you were really gung-ho, then you could host SMTP software, and I know a lot of folks do it, but then you really take on the role of being an email administrator, which means all the whitelisting, setting up feedback loops, etc.
