SendBunny vs MailgunMailgun marks up shared sending infrastructure. SendBunny installs onto SES you already control.

Mailgun runs sending through its own shared infrastructure, and the plan you buy is really buying a slice of that shared tenancy, priced in tiers with a monthly floor that applies whether the month was busy or silent. It is a capable hosted product, but the price is set for the platform, not strictly for the mail actually sent.

SendBunny installs directly onto Amazon SES inside your own AWS account, as a one-click CloudFormation stack, and there is no shared tenancy in between. The $199 license is paid once; sending after that is billed by Amazon at its own published rate, roughly $0.10 per 1,000 emails, and a month with nothing sent costs close to nothing on the platform side.

At 10,000 emails a month, Mailgun's entry tier runs around $15, against roughly $1 in raw Amazon SES fees for the identical volume, a markup of well over ten times for the same emails delivered. At real scale the comparison moves to custom volume pricing on Mailgun's side, which is exactly the kind of negotiated rate that stops being transparent; SendBunny's cost at a million emails a month stays a predictable $100 in SES fees, on top of the $199 already spent.

Plan-floor pricing is easiest to defend during a busy month, when the flat rate looks like a bargain against actual usage. It is hardest to defend during a quiet one, a slow season, a product between launches, a list that gets emailed twice instead of ten times, when Mailgun's minimum plan charge keeps arriving at full price for a fraction of the sending. SendBunny's cost structure inverts that: the license is sunk once, and a quiet month costs close to zero beyond it, because Amazon SES only bills for what actually goes out.

That difference compounds for any team whose send volume is seasonal or bursty rather than a flat monthly number, which describes most marketing sending and a good share of transactional traffic too.

• Keep Mailgun if you rely on its specific routing rules, inbound parsing, or webhook features and would need to rebuild them elsewhere, or you are locked into a negotiated volume contract that already beats list pricing.
• Move to SendBunny if you are tired of paying a plan floor in quiet months, want raw Amazon SES economics with a real UI, or want campaigns and a transactional API from the same owned account.

Mailgun's routing and inbound-parsing features are genuinely deep, and a workflow already built around them is a real switching cost, not just inertia. Weigh that cost against what a plan floor is actually charging for sending that never happens.

1. List the domains and webhooks you rely on in Mailgun before starting, so nothing gets missed in the cutover.
2. Install SendBunny with the one-click AWS deploy, a Create stack step that runs in about ten minutes.
3. Move DNS and Amazon SES verification, then import your contacts using the DNS records the app generates.
4. Repoint API calls to the new send path and retire Mailgun, once traffic on the new stack looks correct.