Mailgun vs Bulko: SMTP Relay Pricing and Features Compared (2026)

Choose Mailgun if you are a developer who needs an HTTP API, webhooks, inbound routing and email validation, and you send a steady volume every month (its Foundation plan covers 50,000 emails for $35). Choose Bulko if you just need SMTP credentials and want to prepay once: 20,000 emails cost $15 with no expiry, while the same volume on Mailgun Basic comes to $33 a month.

Mailgun (owned by Sinch) is an email API service with monthly plans and per-email overage. Bulko SMTP Relay is a plain SMTP server sold in one-time packages. Below are the numbers from both pricing pages as of October 2026, followed by an honest look at what each one does better.

Quick comparison

Pricing

Mailgun's pricing page lists a Free plan (100 emails per day, one custom sending domain), Basic at $15 per month for 10,000 emails with extra messages from $1.80 per 1,000, Foundation at $35 per month for 50,000 (extra at $1.30 per 1,000) or $75 for 100,000 (extra at $1.10), and Scale from $90 per month for 100,000. Foundation and Scale start with a free first month. Bulko's packages are 5K for $5, 20K for $15, 50K for $30 and 150K for $60.

Bulko is cheaper at each of these volumes, and the gap is widest at 20,000 and 150,000. There are two things to weigh against that. First, Mailgun's price buys more than delivery: APIs, webhooks, analytics and log retention are part of the plan. Second, Bulko's default limit is 2,000 emails per day per SMTP account, so sending 150,000 in a single month requires asking [email protected] to raise the limit. Mailgun Basic has no daily cap.

Over a year at 20,000 emails a month, Mailgun Basic with overage comes to $396, against $180 for twelve Bulko 20K packages. Prices checked October 2026, see the Mailgun pricing page for current plans.

Setup and deliverability

With Mailgun you add a sending domain and publish the DNS records it gives you (SPF, DKIM and tracking records) before the domain is verified. SMTP credentials are created for that domain in the control panel, and your software connects to smtp.mailgun.org. The free plan allows one custom sending domain.

Bulko works differently. There is no account review before you can send: you pay for a package and the SMTP credentials are shown in the dashboard and emailed to you immediately. You can send from any address on a domain you control. Verifying the domain is optional but recommended: Bulko gives you a DKIM TXT record (selector bk1) and a CNAME bnc.yourdomain.com for the return path, which lets SPF, DKIM and DMARC align. Without verification, mail still sends.

Mail goes out through Bulko's own MTA, which throttles warm-up per mailbox provider, processes bounces and monitors blocklists. Every message also passes an AI content filter (rules plus AI) that looks for phishing, malware, brand impersonation and scams. Messages that fail are rejected with 554 5.7.1 and are not delivered, so you see the problem immediately instead of finding it later in a reputation report. The default limit is 2,000 emails per day per SMTP account, and [email protected] can raise it on request.

No provider can promise inbox placement, and Bulko does not publish delivery-rate numbers. What decides the result is the same everywhere: authenticated domains, clean lists and content people asked for. The SPF, DKIM and DMARC setup guide and the blacklist checker help with the first two.

When Mailgun is the better choice

• You build on an API. Mailgun's REST API and SDKs suit applications that send from code. Bulko SMTP Relay has no HTTP sending API.
• You need webhooks and logs. Mailgun reports delivery, bounce, open and click events to your endpoints and keeps searchable logs. Bulko does not provide webhooks for the relay.
• You receive email. Mailgun inbound routes can forward or post incoming mail to your app. Bulko is outgoing only.
• You want email validation in the same account. Mailgun sells address validation alongside sending.
• You send high, steady volume and want plan tiers that go into the millions plus an Enterprise option. Bulko does not offer dedicated IPs or SLAs.

When Bulko is the better choice

• No subscription. You pay once, and the emails stay on your balance until you use them. There is no monthly invoice for overage.
• Small or uneven volume. 5,000 emails cost $5 instead of a $15 monthly minimum.
• Crypto payment. Bulko accepts USDT, BTC and other coins, plus Visa and Mastercard via Stripe.
• Fast start. Credentials arrive right after payment, and you can send before you finish DNS work. Verifying the domain later improves alignment.
• Any SMTP software. WordPress plugins, CRMs, scripts, printers and mail servers only need host, port, username and password.

For a wider list, read Mailgun alternatives in 2026 or the best SMTP services by use case.

How to switch to Bulko SMTP

1. Buy a package on the Bulko SMTP Relay page with a card or crypto. Your SMTP username and password appear in Dashboard > SMTP Access and are also emailed to you right after payment.
2. In your app, plugin or server config, replace smtp.mailgun.org with smtp.bulko.io.
3. Pick a port: 587 with STARTTLS (many apps label it "TLS"), 465 with implicit SSL/TLS (often labeled "SSL"), or 2525 with STARTTLS if your hosting provider blocks 587 and 465. Port 25 is not offered for submission.
4. Paste the Bulko username (it looks like smtp_xxxxxxxxxxxxxxxx) and password into the SMTP username and password fields. Authentication is AUTH LOGIN or PLAIN, which every common SMTP library supports.
5. Use a From address on a domain you control. Optionally verify the domain under Sending Domains: Bulko gives you a DKIM TXT record (selector bk1) and a CNAME bnc.yourdomain.com for the return path, so SPF, DKIM and DMARC align.
6. Send a test message before moving all traffic. A 535 reply means the credentials are wrong; see SMTP error 535.

SMTP host: smtp.bulko.io
Port: 587 (STARTTLS) or 465 (SSL/TLS) or 2525 (STARTTLS)
Username: smtp_xxxxxxxxxxxxxxxx
Password: from Dashboard > SMTP Access

If you are unsure which port your software expects, the SMTP ports guide explains the difference between 465, 587 and 2525.

If your application sends through Mailgun's HTTP API rather than SMTP, switch it to an SMTP transport first. Also remove any code that waits for Mailgun webhooks, since Bulko will not call them.

FAQ

Is Bulko cheaper than Mailgun?

Yes at the volumes compared here: $5 versus $15 for 5,000 emails, $15 versus $33 for 20,000, $30 versus $35 for 50,000 and $60 versus $130 for 150,000. Mailgun's price includes APIs, webhooks and logs that Bulko's SMTP relay does not offer.

Does Mailgun have a free plan in 2026?

Yes. The Mailgun Free plan allows 100 emails per day with one custom sending domain. Bulko has no free SMTP plan; its 500 free sign-up credits apply only to the Campaign Platform.

Do I have to verify my domain with Bulko like with Mailgun?

No. With Bulko, verification is optional and mail sends without it. Verifying adds a DKIM record (selector bk1) and a return-path CNAME so SPF, DKIM and DMARC align, which is recommended.

Can I use port 2525 with both services?

Yes. Mailgun listens on 25, 465, 587 and 2525. Bulko offers 587, 465 and 2525. Port 2525 helps when a hosting provider blocks the standard ports.

Is there a daily sending limit on Bulko?

Yes, 2,000 emails per day per SMTP account by default. Support can raise it on request at [email protected].