I'm not sure if this is feasible or not, but I'd love to read an overview of how you are handling the different plans scenario (previous plans setup vs new pay as you go setup) on a technical level. It'd be helpful for any SaaS owners who want to one day do something similar and as far as I know, no one has ever documented this process.

Before if you had a 59 US $ plan (dedicated IP), the cost was 0.59/thousand, so you could send 118k emails.

With the new plan, for 59 US$ you get the dedicated IP and 10k emails. Sending 118k emails with a dedicated IP would cost 113 US$

Love it! I ran into the (free) limits recently during a one-off email blast as part of a new feature rollout. The limit caused a lot of emails to fail.... but MailGun's customer service rectified it in like 5 minutes (at like 2am on a Saturday). Very impressive!

Any idea when the Heroku plans will reflect the pricing changes...?

EDIT: From the article, old plans may be granfathered (if desired)...? If so, how do we switch to new pro-rated on Heroku? Just downgrade the addon?

Thanks for doing this. It makes your pricing now fair and easy for an entrepreneur to plan. I'm currently comparing Mailgun to Mandrill and I'm wondering what makes Bakunin better? Mandrill's prices look great. Can you enlighten me on differences I may be missing?

One feature I'm looking for that mandrill doesn't seem to have is multi-tenancy.

Just a quick note: your pricing calculator does not let me enter any number. I use Czech keyboard layout where numbers are typed with Shift key. This happens in both Firefox and Chrome. Once I switch to English layout, it works fine.

I think you should update your FAQ entry: "What are the differences between the plans you offer?"

Otherwise, looks good :)