I've had something of a bad taste in my mouth regarding MailChannels and the 18 hour outage I had due to massive miscommunication and lack of communications channels with them. Recently, they updated their published pricing, posting a minimum $500/month charges, which now have a form to fill out for custom pricing. They clearly just want large outfits, not smaller hobbyists/independent hostmistresses. In their favor, when the service is working (and that is most of the time), I have had no problems with delivery of messages, but it's just really pricey for what I need.
I've taken a look at two more common SMTP providers in the past few months. First I tried SendGrid, as I do get a fair amount of email from users of their service. I sent about a dozen emails, only to have half bounce due to the SendMail IPs being on 6+ RBLs (the screenshot was from several days later, and it's still on 5!). I reported this to support, but first it took three days for them to get back to me, then I was given a song and dance, and the offer of a 25% discount to start a very large package that was going to be more expensive than MailChannels.
If you upgrade your subscription to Pro 100k level, which uses a dedicated IP address to send mail. This would eliminate the possibility that other SendGrid users could negatively affect your sending IP's reputation and thusly message deliverability. If you're interested in going this route, please do let us know as we can offer a 25% discount for the first three months of your Pro subscription to ease the burden of switching to a more expensive plan.
I've also checked out SMTP2GO, their service has given me no issues. Even as a prospect on their entry level package, I was getting prompt replies. They let me know I could dial up or down my packages as needed, not trying to oversell me, so I'm going to go forward with trying them out, preliminary testing shows excellent deliverability results.
