Software Alternatives & Startups

Smtp4dev VS AgentClara

Compare Smtp4dev VS AgentClara and see what are their differences

Note: These products don't have any matching categories. If you think this is a mistake, please edit the details of one of the products and suggest appropriate categories.

Smtp4dev logo Smtp4dev

Smtp4dev is an all-in-one SMTP server designed to develop and test emails in your applications.

AgentClara logo AgentClara

AgentClara is a UK AI receptionist that answers calls, books clients, and handles follow-ups 24/7 for service businesses and agencies. Free AI agents for website chat, SMS, social media and email included. Set up online with a free number in minutes
Visit Website
  • Smtp4dev Landing page
    Landing page //
    2023-09-24
  • AgentClara Dashboard
    Dashboard //
    2026-08-20
  • AgentClara Analytics
    Analytics //
    2026-08-20
  • AgentClara Analytics 2
    Analytics 2 //
    2026-08-20
  • AgentClara Test your channels
    Test your channels //
    2026-08-20
  • AgentClara Test your agents responses over calls
    Test your agents responses over calls //
    2026-08-20

Smtp4dev features and specs

  • Open Source
    SMTP4dev is open-source, allowing developers to access, modify, and contribute to the code. This promotes community collaboration and transparency.
  • Local Testing
    Provides an easy way to test emails locally without the need to send messages through external servers, which can speed up development and debugging.
  • Cross-Platform
    Compatible with multiple operating systems (Windows, macOS, Linux), making it versatile for developers using different environments.
  • Web Interface
    Features a user-friendly web interface for viewing and managing received emails, simplifying the process for users to interact with the tool.
  • No Configuration Needed
    Runs with minimal configuration, enabling easy setup and use for developers who need a quick solution.

Possible disadvantages of Smtp4dev

  • Limited Features
    Lacks advanced email testing features such as spam score analysis or integration with CI/CD pipelines, which could be needed for more comprehensive testing.
  • Not Suitable for Production
    Designed for local testing and is not intended to be used as a production mail server, limiting its use case to development environments only.
  • Security Concerns
    Running an SMTP server locally might pose security risks if not properly managed, especially when testing with real data.
  • Dependency Management
    Since it's a third-party tool, it can require management of dependencies and regular updates to ensure compatibility with existing workflows.

AgentClara features and specs

  • 24/7 call answering
    Clara answers every business call instantly, day or night, in your business name — no voicemail, no queue, no out-of-hours surcharge.
  • Live calendar booking
    Books appointments directly into your real diary during the call, then sends confirmations and reminders by SMS or email to cut no-shows.
  • Multi-channel AI agents
    Free AI agents for website chat, SMS, social media inbox and email included alongside calls — one assistant across every enquiry channel.
  • Automatic follow-ups
    Chases enquiries that didn't book, so leads don't go cold while you're working. 5.
  • Self-serve setup
    Get a free number and go live in minutes online — no sales call, no quote, no setup fee. Every account starts with £100 of free credit. 6.
  • UK-built and GDPR-native
    UK numbers, UK phrasing and accents, pricing in pounds, and UK GDPR compliance built in from the ground up.
  • Agency white-label
    Agencies and resellers manage every client business under one account with recurring revenue share — no engineering required.

Smtp4dev videos

Sending Email with SMTP4Dev and MailKit (#210)

More videos:

  • Review - send email to localhost using smtp4dev and view in outlook

AgentClara videos

No AgentClara videos yet. You could help us improve this page by suggesting one.

Add video

Category Popularity

0-100% (relative to Smtp4dev and AgentClara)
Email Testing
100 100%
0% 0
SaaS
0 0%
100% 100
Office Suites
100 100%
0% 0
AI
0 0%
100% 100

Questions & Answers

As answered by people managing Smtp4dev and AgentClara.

Which are the primary technologies used for building your product?

AgentClara's answer:

A React and TypeScript web application on a Postgres backend, with real-time voice handled over a persistent WebSocket bridge for low-latency conversation. Large language models power the conversational layer, with dedicated speech and telephony infrastructure for calls, plus integrations for calendars, messaging channels and payments.

What makes your product unique?

AgentClara's answer:

Most AI receptionists answer the phone. Clara staffs the whole front desk: she answers every call 24/7, books clients straight into your live diary, chases enquiries that didn't book, and covers your website chat, SMS, social media inbox and email — with those extra channels included free, not sold as add-ons. She's UK-built, GDPR-native, priced in pounds, and you set her up yourself online in minutes with a free number and £100 of credit — no sales call, no quote.

Why should a person choose your product over its competitors?

AgentClara's answer:

Three reasons. First, channels: rivals are phone-first, so DMs and web chat go unanswered — Clara covers every channel in one place. Second, booking: many entry plans only take messages or send a booking link; Clara books the appointment during the call and sends the confirmation. Third, no sales process: the big UK incumbents quote you after a consultation, while Clara is self-serve with £100 of free credit so you can test her on your real calls before paying anything.

How would you describe the primary audience of your product?

AgentClara's answer:

UK service businesses that lose money to missed calls — gyms, salons, aesthetics clinics, dental practices, estate agents and law firms — where one missed enquiry is a lost booking worth hundreds. The second audience is agencies and resellers who want to offer AI receptionists to their own client book without building the technology themselves.

What's the story behind your product?

AgentClara's answer:

AgentClara was built by a Glasgow gym owner who kept losing members to unanswered calls. The phone rang mid-class, the Instagram DM arrived at 10pm, and the customer joined the gym down the road — not because the service was worse, but because nobody answered. Clara was built to be the employee that always answers, and now does the same job for service businesses across the UK.

User comments

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Social recommendations and mentions

Based on our record, Smtp4dev seems to be more popular. It has been mentiond 2 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.

Smtp4dev mentions (2)

  • How do you guys write end to end test which will trigger a mailer endpoint?
    Depends on the infrastructre setup, but if you're able to specify smtp server the backend will use you can you something like https://github.com/mailhog/MailHog or https://github.com/rnwood/smtp4dev to catch any sent email, regardless of email address and read it via the respective api. Both mailhog and smtp4dev have decent api documentation. Source: over 3 years ago
  • Make smtp server
    If so you could check out smtp4dev, it gives you a locally hosted client that you can use to intercept any mail send out by your app and displays them in a nice web based gui interface so can see what they look like. Source: about 4 years ago

AgentClara mentions (0)

We have not tracked any mentions of AgentClara yet. Tracking of AgentClara recommendations started around Aug 2026.

What are some alternatives?

When comparing Smtp4dev and AgentClara, you can also consider the following products

MailHog - MailHog is an email testing tool inspired by MailCatcher, but easier to install.

Vapi - Voice AI Infrastructure for the Internet

Mailtrap - Email Delivery Platform that delivers just in time.
 Great for businesses and individuals.

Retell AI - API that enables developers to build human-like voice agents

FakeSMTP - FakeSMTP is a Free Fake SMTP Server with GUI for testing emails in applications easily.

MoneyPenny - Track time and expenses, issue professional invoices and manage projects in one place. MoneyPenny is the best solution for your business.