REVIEW
I was offered a review copy by rez445 and here's my unbiased opinion about the tool.
QUALITY
For the last 30 days, my setup was active and the tool was running 24*7 without crashing a single time. Honestly, when someone sends me a v1.0 of their product, I'm expecting it to crash a few times, miss out on several features and be as annoying as it can be since it's the first version but surprisingly, none of that happened to me while using inMailManager and the experience was nothing but smooth.
The tool has immense potential and I like always had several feature suggestions and recommended changes for the OP which he very patiently heard and responded positively that a lot of them will be available in the upcoming release of the tool. Just one slight bug when you press the 'stop' button and the resume, it doesn't always resume and you need to press it back and forth and that fixes it, no bigger and I'm sure that's fixed in the next version too.
PRICE
If you're unsure, it even offers a 3-day free trial, that shows the confidence of the creator unlike several other tools which don't even offer any kind of trials where your only option is to pay and see for yourself, but with this, I'm sure if you know how Instagram and SMTP works, you wouldn't twice to extend your trial and get a monthly/yearly plan for yourself! At the current price, it's a great deal and if you buy the yearly subscription, that would be less than $8 per month which is the price of the coffee which you had early this morning.
SPEED
Recently, putting Instagram and Automation together in one sentence hasn't been very feasible and similarly, you have to careful that when you attach an account here, you don't take it overboard and spam too much with it in your phone to avoid getting action blocked/suspended and keep the scraping active. If you have got quality accounts and HQ proxies then it shouldn't be a problem. Also, when you're just scraping, the speed is faster than scraping + sending emails, so you can just use this as a scraper as well.
And the SMTP function works as promised, it allows you to attach HTML elements and even attachments if needed with the option to add multiple account and everything works pretty smoothly so no complaints there.
COMMUNICATION
OP is an active member of the forum and replies to all messages in less than 24 hours and I'm sure the same/better support will be offered to all the customers of the project so you shouldn't have a problem setting up and getting your queries answered(if any).
Good luck with the sales!