The cheapest way to start sending through an SMTP relay in 2026 is a pay-as-you-go service with no monthly subscription. Bulko is the lowest-commitment option: $5 for 5,000 emails, one time, with no recurring fee, credits that do not expire, and crypto accepted. If you send hundreds of thousands of emails a month and can manage the setup yourself, Amazon SES is the cheapest per email (about $0.10 per 1,000), but it is harder to configure and support is paid.
"Cheapest" depends on how you send. Most SMTP providers are subscription products with a monthly minimum, so a small sender pays for a whole plan whether or not they use it. A pay-as-you-go relay removes that minimum: you buy a block of emails once and send them whenever you want. This guide compares the real entry cost of the main SMTP relay services and shows which is cheapest for low volume, for no-commitment sending, and for high volume at scale.
Pricing below was checked against public plans in 2026. Providers change prices often, so confirm the current number on each provider's pricing page before you buy.
SMTP relay pricing compared (2026)
| Service | Cheapest entry | Monthly minimum | Pay-as-you-go | Free tier | Crypto |
|---|---|---|---|---|---|
| Bulko | $5 one-time (5,000 emails) | None | Yes | 500 welcome credits | Yes |
| Amazon SES | ~$0.10 / 1,000 | None (AWS account) | Yes (usage-based) | 3,000/mo first year | No |
| Brevo | from ~$9/mo | Yes (paid tiers) | No | 300/day (9,000/mo) | No |
| SMTP2GO | from ~$10/mo | Yes (paid tiers) | No | 1,000/mo | No |
| SendGrid | from ~$19.95/mo | Yes | No | 100/day trial | No |
| Mailgun | from ~$15/mo | Yes | No | Trial only | No |
| Postmark | from ~$15/mo (10,000) | Yes | No | 100 test sends | No |
Cheapest to start and cheapest for low volume
If you send a few thousand emails and do not want a recurring bill, a pay-as-you-go relay is the cheapest option because there is no monthly minimum to cover. Bulko sits here: one payment of $5 gives you 5,000 emails, the credits do not expire, and there is no subscription to cancel later. That is different from SendGrid, Mailgun or Postmark, where the smallest paid plan is a monthly fee you pay every month even if you send nothing.
Two providers offer generous free tiers for very low volume: Brevo (300 emails per day) and SMTP2GO (1,000 per month). If your volume fits inside a free tier permanently, that is the cheapest of all. The moment you outgrow it, you move to a monthly plan, which is where pay-as-you-go becomes cheaper for irregular sending.
Cheapest per email at scale
At high volume the ranking changes. Amazon SES bills roughly $0.10 per 1,000 emails, which is the lowest per-email price on the market, and Brevo's and Elastic Email's transactional add-ons are close. The trade-off is setup and support: SES requires you to configure sending, manage your own reputation and pass a review to leave the sandbox, and help is a paid AWS support plan. You are trading convenience for the lowest unit price.
Managed relays such as SendGrid, Mailgun and SMTP2GO sit between $0.40 and $1.00 per 1,000 at scale. You pay more per email for deliverability tooling, dashboards and support you would otherwise build yourself.
Where Bulko fits
Bulko is a managed SMTP relay sold as pay-as-you-go blocks rather than a subscription. The credentials work in any SMTP-capable software or script.
- Pricing: SMTP Starter $5 for 5,000 emails, Growth $15 for 20,000, Business $30 for 50,000, Enterprise $60 for 150,000. That is $1.00 per 1,000 at the entry block and $0.40 per 1,000 at the top block.
- No subscription: you buy a block once, credits do not expire, and there is no monthly minimum.
- Ports: 587 (TLS / STARTTLS) and 465 (SSL). Same username and password on both.
- Auth: LOGIN / PLAIN over TLS.
- Payment: card and crypto.
- Safety: every message is scanned by an AI content filter; blocked messages return SMTP 554 and do not consume credit.
Bulko is the cheapest choice when the priority is starting fast with no recurring commitment, paying in crypto, or sending irregular volume that does not justify a monthly plan. It is not the cheapest per email at very high, steady volume, where Amazon SES wins on unit price.
How to choose the cheapest SMTP for your case
- Low or irregular volume, no commitment: a pay-as-you-go relay like Bulko. No monthly fee, $5 to start.
- Permanently tiny volume: a free tier (Brevo 300/day or SMTP2GO 1,000/mo).
- Very high, steady volume with in-house setup: Amazon SES for the lowest per-email price.
- Managed features and support at scale: SendGrid, Mailgun or SMTP2GO paid plans.
- Paying with crypto: Bulko.
Frequently asked questions
What is the cheapest SMTP relay service?
For low or irregular volume, the cheapest is a pay-as-you-go relay with no monthly minimum, such as Bulko at $5 for 5,000 emails. For very high, steady volume, Amazon SES is cheapest per email at about $0.10 per 1,000, in exchange for more setup.
Is there a cheap SMTP service with no monthly subscription?
Yes. Bulko sells SMTP access as one-time blocks (from $5 for 5,000 emails) with no subscription and credits that do not expire. Amazon SES also has no fixed monthly fee but bills per use inside an AWS account.
What is the cheapest SMTP for low volume?
If your volume fits a free tier permanently, Brevo (300/day) or SMTP2GO (1,000/month) cost nothing. For volume above a free tier but too small for a monthly plan, a pay-as-you-go block like Bulko's $5 for 5,000 emails is usually cheaper than any subscription.
Can I pay for an SMTP service with crypto?
Bulko accepts crypto as well as card. Most mainstream relays (SendGrid, Mailgun, SMTP2GO, Postmark) accept card only.
What SMTP ports does Bulko use?
Bulko supports port 587 (TLS / STARTTLS) and port 465 (SSL). Use 587 if your app asks for TLS or STARTTLS, and 465 if it only offers SSL. The username and password are the same on both.
See Bulko SMTP Access or compare all packages on the pricing page.
