Mailgun vs Loops for Solo Developers

Quick Comparison

Mailgun Overview

Mailgun is a mature, developer-oriented email platform owned by Sinch. It handles every type of email: transactional, bulk marketing, and operational. The API supports both REST and SMTP, which means you can integrate it whether you are writing code or configuring a CMS. Features include email validation, inbound routing, mailing list management, and detailed delivery analytics.

The platform is built for flexibility. You can send a single transactional email, manage subscriber lists for newsletters, validate email addresses before sending, and receive inbound emails for processing. The SDKs are available for every major language, and webhooks let you track delivery events in real time.

Mailgun's free tier sends 100 emails per day with one custom domain and one day of log retention, which is really a sandbox for testing. The Foundation plan at $35/month (first month free) unlocks 50,000 emails, the template builder, full inbound routing, and five days of log retention. A dedicated IP shows up one tier higher on Scale at $90/month for 100,000 emails. For solo developers who need a general-purpose email platform that handles multiple use cases, Mailgun covers the bases without requiring multiple services.

Loops Overview

Loops is built from the ground up for SaaS companies. Instead of being a generic email delivery service, it is designed around the SaaS user lifecycle: signup, onboarding, engagement, conversion, and retention. Every feature supports that workflow.

The visual flow builder is the centerpiece. You create automated email sequences triggered by user events. A user signs up, they get a welcome email. Three days later, they get an onboarding tip. If they have not activated a key feature after a week, they get a nudge. All of this is configured visually without writing scheduling logic in your backend.

Contact management tracks user properties (plan type, last login, features used) and lets you segment your audience for targeted campaigns. Transactional email is supported through the API for one-off sends like password resets. But Loops is really about ongoing user communication, not just individual message delivery.

The free tier supports up to 1,000 contacts and 4,000 sends every 30 days (marketing and transactional combined), with a Loops footer on every email. The Starter plan at $49/month covers 5,000 contacts with unlimited sends, and every paid tier includes all features. The next step up, Growth, starts at $99/month for 10,000 contacts.

Key Differences

Philosophical approach. Mailgun is an email delivery service. It sends what you tell it to send. Loops is an email engagement platform. It helps you decide what to send, when to send it, and to whom. If you want infrastructure, pick Mailgun. If you want strategy, pick Loops.

Automation depth. Loops has a visual automation builder with triggers, delays, conditions, and branching. You design entire email journeys without code. Mailgun has no automation features. To build a drip campaign with Mailgun, you write the timing and conditional logic in your application and call Mailgun's API at each step. That is a significant amount of custom code.

Contact management. Loops tracks user properties, events, and segments. You can see which users are on free vs paid plans, who has been inactive for two weeks, and send targeted messages to each group. Mailgun has basic mailing list management but nothing close to the CRM-like contact tracking Loops offers.

Email validation and inbound routing. Mailgun validates email addresses and processes inbound emails. Loops does neither. If you need to verify addresses before sending or receive and parse incoming emails, Mailgun handles those use cases.

Pricing model. Mailgun charges based on emails sent. Loops charges based on subscribed contacts stored, with unlimited sends on every paid plan. These are different axes, so the cheaper option flips depending on whether your cost driver is volume or audience size. A SaaS with 3,000 contacts sits on Loops Starter at $49/month no matter how many emails it sends. On Mailgun the same audience could fit inside the $15/month Basic plan (10,000 emails) if you send lightly, or push up to Foundation at $35/month once you cross 10,000 sends in a month. The Real Cost section below works a concrete example.

Target audience. Mailgun works for any type of application: e-commerce, SaaS, media, internal tools. Loops is specifically designed for SaaS products and their user lifecycle. If you are building a SaaS, Loops speaks your language. If you are building something else, Mailgun is more versatile.

When to Choose Mailgun

• You need a general-purpose email platform that works for any application type
• Email validation is important for maintaining sender reputation
• You need inbound email processing for reply parsing or support flows
• You want SMTP relay support alongside REST API
• You are building something other than a SaaS product

When to Choose Loops

• You are building a SaaS and want purpose-built email tooling
• Visual automation builders save you from coding email sequence logic
• Contact segmentation and user lifecycle tracking are part of your strategy
• You want transactional and marketing email in one SaaS-focused platform
• Speed of setting up onboarding flows and drip campaigns matters more than raw infrastructure features

By the Numbers (2026)

Checked on 2026-05-28. Both are commercial SaaS products, so the meaningful data here is pricing, tier limits, and the billing unit each one uses.

Mailgun (owned by Sinch)

• Free: $0, 100 emails per day, 1 custom domain, 1 inbound route, 1-day log retention, 2 API keys.
• Basic: from $15/month, 10,000 emails/month, no daily cap, overage from $1.80 per 1,000 emails.
• Foundation: $35/month (first month free), 50,000 emails/month, template builder, full inbound routing, 5-day log retention, overage from $1.30 per 1,000 emails, validations from $1.20 per 100.
• Scale: $90/month (first month free), 100,000 emails/month, one dedicated IP, 5,000 included validations, SAML SSO, 30-day log retention, overage from $1.10 per 1,000 emails.
• Enterprise: custom.
• Billing unit is emails sent. REST and SMTP, plus a Routes API for inbound mail and an email validation service.

Loops

• Free: $0, up to 1,000 contacts, 4,000 sends per 30 days (marketing and transactional combined), Loops footer on every email.
• Starter: $49/month, 5,000 contacts, unlimited sends, all features.
• Growth: $99/month (10,000 contacts), $149 (15,000), $199 (25,000), $249 (50,000), all with unlimited sends.
• Scale: $399/month, 100,000 contacts.
• Enterprise: custom, above 100,000 contacts.
• Billing unit is subscribed contacts. Visual automation flows, event-based API, contact properties and segmentation, plus transactional sends through the API at no extra charge.

The headline: Mailgun starts cheaper ($15 to $35 versus $49) and scales on send volume, while Loops bundles unlimited sends and bills purely on how many people you keep on your list.

Real Cost at Solo-Dev Scale

Take a realistic solo SaaS: 3,000 subscribed users, sending a weekly product newsletter plus the usual lifecycle and transactional mail (welcome, onboarding nudges, password resets, receipts). Call it roughly 5 emails per user per month.

Assumptions:

• 3,000 contacts.
• 5 emails per contact per month, so about 15,000 emails sent per month.
• One sending domain, no dedicated IP, no email validation purchased.

On Loops: 3,000 contacts lands on the Starter plan at $49/month flat. Sends are unlimited, so the 15,000 emails do not change the bill. If your list doubles to 6,000 contacts you cross into Growth at $99/month, again regardless of send volume.

On Mailgun: the cost driver is the 15,000 emails, not the 3,000 contacts. The Basic plan includes 10,000 emails for $15/month, so you would either pay Basic plus overage on the extra 5,000 emails (5 x $1.80 = $9, for about $24/month), or step up to Foundation at $35/month for the full 50,000-email headroom. Foundation is the cleaner choice here because it also unlocks inbound routing and the template builder. Either way Mailgun comes in under Loops at this scale, and the gap is mostly your time, because Mailgun gives you delivery and nothing else.

So at 3,000 users sending moderately, Mailgun is roughly $24 to $35/month against Loops at $49/month. The $14 to $25 monthly difference is real but small. The bigger number is the engineering hours Loops saves you on the automation builder, which you would otherwise write and maintain against Mailgun's API. If your sending spikes (say a daily digest pushing past 50,000 emails/month), Mailgun's volume-based bill climbs while Loops stays flat at $49 until your contact count grows. Pick the axis that matches your product: pay for volume on Mailgun, pay for audience on Loops.

The Verdict

These tools target different developers with different needs. If you are building a SaaS product, Loops is almost certainly the better choice. The visual automation builder, contact management, and SaaS-specific workflows save you days of custom development compared to building the same thing on Mailgun's API. Setting up a full onboarding email sequence in Loops takes an afternoon. Building it with Mailgun takes days of backend code.

If you are not building a SaaS, or if you need features like email validation, inbound routing, or high-volume bulk sending, Mailgun is the more versatile platform. It handles use cases that Loops was never designed for.

My take for solo SaaS developers: go with Loops. The time savings from the automation builder alone justify the cost. You will ship your email strategy in hours instead of days, and that time goes back into building features your users actually pay for. Mailgun is a solid platform, but for SaaS email, Loops was purpose-built and it shows.

Sources

All figures checked on 2026-05-28.

• Mailgun pricing (plan prices, email limits, free-tier and overage rates)
• Mailgun API reference (overview) (REST and SMTP API, email validation)
• Mailgun Routes API (inbound routing)
• Loops pricing (plan prices, contact tiers, unlimited sends)
• Loops free plan docs (1,000 contacts, 4,000 sends per 30 days, Loops branding)
• Loops transactional email docs (event-based API, transactional sends included)