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SMTP Relay Service

Send Emails From Any Software

Get SMTP credentials in minutes and send from any app, script or email tool. One-time packages from $5 for 5,000 emails, paid by card or crypto. No subscription, no expiry.

Get SMTP Credentials View Pricing
  • Setup in 2 minutes
  • Works with any software
  • Ports 587 / 465 / 2525

How It Works

Three simple steps to start sending emails from your own software

01

Choose a Package

Pick the right volume for your needs. Pay once, use anytime — no subscriptions.

02

Get Credentials Instantly

Receive your SMTP server, login, and password immediately after payment.

03

Start Sending

Plug the credentials into any email software, script, or application and send.

SMTP relay

Why Use Our SMTP Relay

Managed Sending Infrastructure

Mail goes out through our own MTA with warm-up throttling per mailbox provider, automatic bounce handling and blocklist monitoring.

Send From Your Own Domain

Verify your domain in a few DNS records and every message is DKIM-signed with your key and uses your return-path, so SPF, DKIM and DMARC align.

Real-Time Analytics

Track sent emails, delivery status, and remaining credits in your dashboard.

Any Software

Works with Thunderbird, Outlook, PHP mail(), Python smtplib, Node.js, custom scripts — anything that supports SMTP.

Instant Setup

Start sending right after payment. Domain verification is optional and can be added later for better inbox placement.

Pay As You Go

No monthly subscriptions. Buy a package, use it at your own pace. Credits never expire.

AI Content Filter — Built In

Every message you send through our SMTP relay is automatically scanned by a hybrid filter (rule-based heuristics + Gemini AI) for phishing, malware, brand impersonation, and scam patterns. Anything that fails returns SMTP 554 5.7.1 and is never delivered.

This protects the reputation of our sending IPs for every customer. Legitimate marketing, transactional and B2B cold-outreach email passes through as usual. See the Acceptable Use Policy.

Python · PHP · Node.js

Simple Integration

Just standard SMTP — no proprietary APIs or SDKs. Use the same code you already know.

  • Standard SMTP ProtocolPort 587 (STARTTLS), 465 (SSL/TLS) or 2525 (STARTTLS), login and password authentication
  • Any Programming LanguagePython, PHP, Node.js, Ruby, Go, Java, C# — if it can send email, it works
  • No Migration NeededJust swap SMTP host, login, and password in your existing configuration
Pythonsmtplib
1import smtplib
2from email.mime.text import MIMEText
3
4msg = MIMEText("Hello from Bulko!")
5msg["Subject"] = "Test Email"
6msg["From"] = "[email protected]"
7msg["To"] = "[email protected]"
8
9# Connect to Bulko SMTP
10server = smtplib.SMTP("smtp.bulko.io", 587)
11server.starttls()
12server.login("your_login", "your_password")
13server.send_message(msg)
14server.quit()
Works with the tools you already useStep-by-step settings with exact fields and code:
DjangoGhostGrafanaLaravellistmonkMakeMauticn8nNextcloudNodemailerPHPMailerPythonSupabaseThunderbirdWordPressZapierAll guides

Pricing

Simple, Transparent Pricing

Pay once by card or crypto. No subscription, no hidden fees, unused emails never expire.

Baserate

SMTP Relay 5K

5,000 emails

$5$1.00/1K
Emails5,000
  • SMTP credentials
  • Ports 587 / 465 / 2525
  • Never expires
  • Real-time stats
Get Started
−25%

SMTP Relay 20K

20,000 emails

$15$1.00 $0.75/1K
Emails20,000
  • SMTP credentials
  • Ports 587 / 465 / 2525
  • Never expires
  • Real-time stats
Get Started
−40% Most Popular

SMTP Relay 50K

50,000 emails

$30$1.00 $0.60/1K
Emails50,000
  • SMTP credentials
  • Ports 587 / 465 / 2525
  • Never expires
  • Real-time stats
Get Started
−60%

SMTP Relay 150K

150,000 emails

$60$1.00 $0.40/1K
Emails150,000
  • SMTP credentials
  • Ports 587 / 465 / 2525
  • Never expires
  • Real-time stats
Get Started

These are SMTP relay packages. Campaign Platform credits (lists, AI personalization, follow-ups) are sold separately on the campaign pricing page.

Who Is This For

Works with any software

Developers

Add email sending to your app or script with standard SMTP. No API integration needed.

Marketers

Use with your favorite email tool — Thunderbird, mail merge plugins, or bulk senders.

Businesses

Send transactional emails from your CRM, ERP, or custom internal systems.

Automation

Integrate into CI/CD pipelines, monitoring alerts, cron jobs, or any automated workflow.

FAQ

Frequently Asked Questions

Still have questions?
Our docs have more details about setup, sending and best practices.

Read the documentation
What SMTP settings should I use?
Serversmtp.bulko.ioPort587 (STARTTLS) · 465 (SSL/TLS) · 2525 (STARTTLS)SecurityTLS requiredAuthLogin and password from your dashboard
Do credits expire?

No. Once purchased, your email credits never expire. Use them at your own pace.

Can I use this with my own domain?

Yes. Use a From address on a domain you control. For the best inbox placement, verify the domain under Sending Domains: we give you a DKIM record and a return-path CNAME so SPF, DKIM and DMARC align.

What software is compatible?

Any software that supports SMTP: Thunderbird, Outlook, PHP mail(), Python smtplib, Node.js Nodemailer, WordPress plugins, CRM systems, custom scripts, and more.

Is there a daily sending limit?

Yes. Each SMTP account can send up to 2,000 emails per day by default. If you need more, email [email protected] and we will raise it after a quick review.

What payment methods do you accept?

Cards (Visa, Mastercard) and cryptocurrency, including USDT and BTC.

Can I send cold emails?

Yes, B2B cold outreach to business addresses is allowed if you identify yourself, include an opt-out and honor it. Purchased lists, phishing and fraud are not. Full rules: Acceptable Use Policy.

My connection fails on port 465 or 587. What should I do?

Match the port to the encryption setting: 587 and 2525 use STARTTLS (often called "TLS" in apps), 465 uses implicit SSL/TLS (often called "SSL"). If your host blocks outgoing 587/465, use 2525.

Do the 500 free sign-up credits work with SMTP?

No. The free credits are for the Campaign Platform. SMTP relay packages are separate and start at $5 for 5,000 emails.

Do you offer refunds?

Yes, within 14 days if the package is unused. See the refund policy.

Explore More Tools
Scripts Parsers Validators SMTP Guides SMTP Errors Blog

Ready to Start Sending?

Get your SMTP credentials in under 2 minutes and start sending from any software today.

  • 587 · 465 · 2525
  • Never expires
  • No monthly subscription
Get SMTP Credentials View Pricing