For bulk sending you need an SMTP relay (a sending service) or your own mail server, not a personal mailbox: regular email providers such as Yandex Mail cap SMTP sending at a few hundred messages a day. A relay costs a few dollars per several thousand emails, and mail stays out of spam when your domain has SPF, DKIM and DMARC and you only email people who agreed to hear from you.
Why a regular mailbox does not work
Personal mail is built for conversations, not campaigns. The Yandex Mail help page, for example, lists daily limits of 300 emails via a mail client or SMTP, 1,000 via the website and 50 via the mobile app. Each recipient, including CC and BCC, counts as a separate email. Going over the limit blocks sending for 24 hours, and the spam filter can block you earlier if it sees repetitive promotional mail. Yandex itself recommends Yandex 360 for Business with Yandex Mailings for bulk sending.
Other free providers work the same way: low limits that can change without notice, and you can lose the whole mailbox over one campaign.
Three ways to get an SMTP server for bulk email
| Option | Cost | Pros | Cons |
|---|---|---|---|
| Mailbox (Yandex, Mail.ru, Gmail) | Free or the mail plan price | Nothing to set up | Low daily limits, risk of mailbox suspension |
| SMTP relay | Pay per volume | Higher limits, bounce handling, DNS guidance | Domain setup and provider rules apply |
| Own server (Postfix, Exim on a VPS) | VPS rental | Full control | IP reputation, blocklists, port 25 blocked by many hosts |
What an SMTP relay costs: Bulko as an example
Providers price differently: monthly subscriptions, per-1,000 rates or one-time packages. Bulko SMTP Relay sells one-time packages with no subscription, and unused emails never expire:
| Package | Price | Per 1,000 |
|---|---|---|
| 5,000 emails | $5 | $1.00 |
| 20,000 emails | $15 | $0.75 |
| 50,000 emails | $30 | $0.60 |
| 150,000 emails | $60 | $0.40 |
You can pay by Visa or Mastercard (via Stripe) or with crypto (USDT, BTC and other coins). Unused packages are refundable within 14 days. There is no free SMTP trial.
When comparing services, look beyond the per-1,000 price and check whether unused volume expires at the end of the month. If you send unevenly, say one campaign a quarter, a subscription can cost more than it seems.
How to connect an SMTP relay
Every app or CMS asks for roughly the same fields: host, port, encryption, username and password. For Bulko:
- Host:
smtp.bulko.io - Port: 587 with STARTTLS (often labeled "TLS"), 465 with SSL/TLS ("SSL"), or 2525 with STARTTLS if your host blocks 587 and 465
- Username: looks like
smtp_xxxxxxxxxxxxxxxx; it and the password are in Dashboard under SMTP Access and emailed after payment - From address: any address on a domain you control
Port 25 is not offered for submission. For the details on ports, see SMTP ports 25, 465, 587 and 2525.
A relay only sends. Replies go to the From or Reply-To mailbox, so that address must exist and be monitored.
Staying out of spam: domain setup
- SPF lists the servers allowed to send for your domain. Check it with the SPF checker.
- DKIM signs each message. When you verify a domain in Bulko (Sending Domains), you get a TXT record with selector
bk1. - DMARC tells receivers what to do with mail that fails checks. It only passes when SPF or DKIM aligns with the From domain.
Bulko also gives you a CNAME bnc.<your domain> for return-path so SPF, DKIM and DMARC align with your domain. Mail still sends without verification, but verification improves your odds of reaching the inbox.
Staying out of spam: content and list
- Email only people who opted in. Purchased lists and unsolicited mail to personal addresses lead to complaints and blocks, and Bulko's acceptable use policy prohibits them.
- Offer an opt-out. A link or a simple "reply stop" lowers spam complaints.
- Clean your list. Remove addresses that hard bounce; a high bounce rate hurts reputation.
- Ramp up gradually. A new domain should not jump straight to tens of thousands of emails. Bulko's default limit is 2,000 emails per day per SMTP account, raised on request via [email protected].
- Do not impersonate. Bulko's content filter (rules plus AI) rejects phishing and brand impersonation with
554 5.7.1. - Separate your streams. Send transactional mail (orders, password resets) and marketing campaigns from different addresses or subdomains, so complaints about promotions do not hurt the messages users are waiting for.
- Watch blocklists. If delivery suddenly drops, run the blacklist checker.
When your own server makes sense
Running Postfix or Exim makes sense if you have an admin, large steady volume and want full control. You handle PTR, TLS, SPF, DKIM, DMARC, bounce processing and monitoring. Many clouds also block outbound port 25 (Google Cloud does for external destinations), and mailbox providers are wary of new IPs with no history. For a website, store or CRM, a relay is usually simpler and cheaper.
FAQ
Can I send bulk email through Yandex SMTP?
Only small volumes. Yandex Mail help caps SMTP sending at 300 emails a day, counting every recipient. For bulk sending, Yandex recommends Yandex 360 for Business with Yandex Mailings, or use a dedicated sending service.
Is there a free SMTP server for bulk email?
Free options are usually capped or require your own infrastructure. Bulko has no free SMTP tier; the smallest package is $5 for 5,000 emails.
Should I use port 465 or 587?
Both encrypt the connection. Use 587 with STARTTLS when your app supports it, 465 with SSL/TLS when the app only offers "SSL", and 2525 if your host blocks both.
Can I send cold email through an SMTP relay?
Bulko allows B2B outreach to business addresses with an honest sender and an opt-out. Purchased lists and unsolicited mail to personal addresses are prohibited.
Why does my mail go to spam even though SMTP works?
Usually SPF, DKIM or DMARC is missing, the domain is new and sending too much too soon, or the list has many invalid addresses. Check your DNS records and start with smaller volumes.
