How to Build an AI Prospecting Email Agent That Finds Leads and Emails Them Safely
Build an AI prospecting agent that researches companies, drafts relevant first emails and sends only through a send gate it cannot bypass. Free open-source code.
Postbox Services
Land Your Emails in the Inbox. Securely. Every Time.
Expert AI Email Deliverability and Email Security Consulting for Growth-Focused Businesses
Transform your email deliverability and email security with cutting-edge AI technology and expert consultation. We ensure your messages reach the inbox, not spam folders.
500+
Clients Served
100M+
Emails Delivered
Free Tools
Free Deliverability Tools - The Same Checks We Run in Paid Audits
Eight free tools, no signup needed. Run the checks yourself - and if something looks wrong, that is exactly what we fix.
FREE
Postbox Mailtester
Send one test email, get a full deliverability audit - spam score, authentication, blacklists, rendering.
Run a spam test FREEPostbox Spoof Check
Can strangers send email as your domain? Test your spoofability and BEC exposure in seconds.
Check my domain FREEPostbox Blacklist Checker
Is your domain or sending IP on a blacklist? Checks the lists that actually affect delivery.
Check blacklists FREEPostbox DMARC Monitor
A weekly digest of everyone sending as your domain - passes, failures and new sources.
Start monitoring FREEPostbox MX Tools
18 DNS and deliverability lookups in one place - SPF, DKIM, DMARC, MX, PTR and more.
Open the toolbox FREEPostbox TLS-RPT Monitor
Are your emails delivered over secure TLS? Get reports when encryption fails in transit.
Check TLS readiness FREEPostbox APRF Monitor
Where does your mail really land? A weekly plain-English digest of inbox placement and engagement, straight from mailbox providers.
See where mail lands FREEPostbox Redirect Checker
Where does that link really go? Trace any URL through its full redirect chain to the real destination - expand shorteners, catch phishing redirects.
Trace a link FREEPostbox AI Discoverability Checker
Can AI answer engines find and cite your site? Grade your robots.txt AI-crawler policy, sitemap and llms.txt - A to F.
Check AI visibilityTrusted by 500+ clients · the free tools run the same engines as our paid audits · no account, no credit card · See all tools
Our Services
Comprehensive Email Deliverability and Email Security Solutions
From audits to full infrastructure management, we provide end-to-end email deliverability and email security services powered by AI and industry expertise.
Email Deliverability
Landing in spam, open rates sliding, or blacklisted? Diagnose it, fix it, and keep it fixed.
Learn MoreEmail Infrastructure & Tools
The plumbing done right: authentication, sending domains, warmup, and the platform behind it all.
- SPF / DKIM / DMARC / BIMI setup
- Large-scale sending platforms & mail servers
- ESP and tool implementation
- Campaign management & team training
Cold B2B Email
Outbound that reaches inboxes and books meetings - infrastructure, lists, copy and sending, done safely.
- Cold-safe sending infrastructure
- Domain & mailbox setup, warmup
- List building & cleaning
- Campaign setup & deliverability care
Email Security
Stop spoofing, phishing and BEC before they reach anyone - audit it, harden it, monitor it.
Learn More
New Product
New from Postbox Services: PSI Inbox
Mail for two readers: you and your AI. PSI Inbox is a mailbox that lives inside your AI assistant.
Visit PSI InboxTrusted by Businesses Like Yours
Testimonials
"Working with Sandeep at Postbox Services is a pleasure. He is a consummate professional who truly knows his craft. Highly recommended for any email deliverability challenge."
"Postbox Consultancy Services conducted an email deliverability audit for us and the results were outstanding. Detailed, actionable, and delivered on time."
"Sandeep and his Postbox Services team know their way around email deliverability better than anyone we have worked with. A genuine expert."
"Sandeep is seriously a genius. Fast response time, understood the problem immediately, and fixed issues that had been hurting us for months."
"Postbox Consultancy Services is extremely helpful in reaching out to the right audience. Our open rates improved significantly after their audit."
"Working with Sandeep at Postbox Services is a pleasure. He is a consummate professional who truly knows his craft. Highly recommended for any email deliverability challenge."
"Postbox Consultancy Services conducted an email deliverability audit for us and the results were outstanding. Detailed, actionable, and delivered on time."
"Sandeep and his Postbox Services team know their way around email deliverability better than anyone we have worked with. A genuine expert."
"Sandeep is seriously a genius. Fast response time, understood the problem immediately, and fixed issues that had been hurting us for months."
"Postbox Consultancy Services is extremely helpful in reaching out to the right audience. Our open rates improved significantly after their audit."
FAQs
My open rates are continuously going down and my emails land in spam. How can you help?
Delivery problems stem from various factors that require proper analysis. An email deliverability audit identifies the underlying issues - authentication gaps, reputation problems, content triggers, or infrastructure faults - and gives you a prioritised fix list.
Can Postbox Services provide us consultancy while we do our own stuff?
Yes. We work as external consultants or auditors, assisting your internal teams in managing email delivery themselves. We train, advise, and review without needing to take over your operations.
What is the best open/click rate Postbox Services assure?
Rates depend on your list quality, industry, content, and sending history. No honest consultant guarantees specific numbers. What we guarantee is a thorough audit, actionable recommendations, and measurable improvement in deliverability metrics.
We are looking to build email infrastructure which can handle few million emails daily. Can Postbox Services help?
Yes. We design and build sending systems at any scale - from startup outreach setups to enterprise-grade platforms handling tens of millions of messages per day.
Where can I host my email infrastructure?
It depends on your volume, compliance requirements, and budget. We evaluate options including AWS SES, dedicated SMTP providers, self-hosted MTAs, and hybrid setups - and recommend the right fit for your specific situation.
From the Blog
Building an AI Agent That Sends Email? Treat It Like a Bulk Sender
An AI agent that emails people is a sender like any other, and the Gmail and Microsoft rules apply from the first message. An eight-step checklist for builders: domains, a send gate, one suppression list, one-click unsubscribe, caps, reply handling, honest identity and monitoring.
How to Run a Spam Test or Email Deliverability Audit from ChatGPT, Claude & Grok - 8 Real Examples
Connect one MCP server and run real email checks from ChatGPT, Claude or Grok: blacklists, spoofing, redirect traces, spam tests, WHOIS - with 8 real examples.
Brand Impersonation in Email: The Four Attacks, and What Actually Stops Each One
The four email brand-impersonation attacks - display-name, trusted-brand lures, DKIM replay and exact-domain spoofing - shown with real headers and the defense that stops each.