Quick answer
Debug Mail - Debug Mail wins for most small teams that only need a fake SMTP inbox for testing, while Mailtrap wins if you also need a sending service and broader email ops features beyond sandboxing.
How the free tiers compare
These products overlap on email testing, but they are not shaped the same. Debug Mail is narrowly focused on hosted fake SMTP for QA: one project, two team members, unlimited test emails, limited forwarding, and small mailbox storage on the free tier. That makes it easy to adopt for a small app team that just wants to capture outbound mail and inspect it. Mailtrap’s free tier is more of a split product: it includes a sending limit plus a sandbox, logs, domains, contacts, and a single user. That gives you more breadth if you are evaluating transactional sending as well as testing, but the free plan is tighter on collaboration and clearly gates more of the useful operational features. For pure test-email workflows, Debug Mail is simpler and less constrained. For teams that want both testing and sending in one platform, Mailtrap is the more expansive fit.
Debug Mail vs Mailtrap free tier, side by side
| Debug MailFTV 47 | MailtrapFTV 37 | |
|---|---|---|
| Free projects / sandboxesDifferent product shapes: Debug Mail is project-based, Mailtrap’s free plan includes one sandbox. | 1 project | 1 sandbox |
| Team / user accessDebug Mail is more friendly for a tiny shared workflow. | Up to 2 team members | 1 user account |
| Test email volumeMailtrap’s free sandbox testing is much more limited, though its sending product also has separate sending limits. | Unlimited test emails per day | 50 test emails per month |
| Forwarding / deliveryMailtrap’s free plan is more about sending and sandboxing than forwarding captured mail. | Up to 1 email per day forwarding | Not listed on the free tier |
| Mailbox / log storageThese are not directly comparable, but both constrain how far back you can inspect messages. | 10 MB mailbox storage per team | 3 days of email logs retained |
| Sending volumeMailtrap’s free plan includes a separate sending limit that Debug Mail does not offer. | Not included | 150 emails per day, 4,000 emails per month |
| Credit card requiredOnly Debug Mail explicitly says no credit card is required. | No card required | Card requirement not stated |
After you outgrow the free tier
Debug Mail uses per-seat pricing on paid tiers, starting at Silver for $2 per user per month after a 2-week trial, then Gold at $5 per user per month. Mailtrap’s paid pricing is flat by plan, starting at Basic for $15/month, then stepping through higher flat tiers as sending volume and account limits rise. For tiny teams, Debug Mail is much cheaper if you only need test inboxes. Mailtrap gets expensive faster, but it bundles a real sending product, higher email limits, and more operational features.
Cost at real usage
| Usage | Debug Mail | Mailtrap |
|---|---|---|
| 2 users, sandbox testing onlyDebug Mail is per seat on paid tiers; Mailtrap’s first paid tier is flat and includes 3 users. | $4/mo | $15/mo |
| 10k emails/month sendingMailtrap’s Basic tier covers 10,000 emails/month; Debug Mail does not list a sending plan. | Not available | $15/mo |
| 100k emails/month sendingMailtrap’s Business tier includes 100,000 emails/month. | Not available | $85/mo |
| 250k emails/month sendingMailtrap lists a $200/month Business tier at 250,000 emails/month. | Not available | $200/mo |
Estimates, not quotes. Usage-based rates change - verify with the vendor's pricing page before committing.
When to pick each one
Pick Debug Mail when…
- You only need a fake SMTP inbox to catch signup, reset, and notification emails during development.
- You want unlimited test emails on a free plan for a small team of up to 2 members.
- You need forwarding for a light QA workflow and can live with 1 forwarded email per day.
- You prefer a free tier with no credit card required.
- You want to keep setup simple around one project and a shared mailbox.
Pick Mailtrap when…
- You need one platform that covers both email sending and sandbox testing.
- You want a free plan with 1 domain, 100 contacts, and 3 days of logs for basic email operations.
- You are evaluating transactional email at low volume and need a 4,000 emails/month sending cap.
- You only need one user on the free plan and do not need much collaboration.
- You expect to grow into dedicated IP, longer log retention, or much larger sending limits.
Bottom line
For the most common builder use case, Debug Mail is the better free-tier choice if your goal is simply to test app email flows with a small team and no card on file. It stays focused, has unlimited test emails on the free plan, and gives enough shared access for early development. Mailtrap is the better pick only if you want to test and send from the same vendor, or if you already know you will need logs, domains, and sending limits that grow into a paid email platform.
Read the full listings: Debug Mail and Mailtrap. Scores use the FTV methodology at /ftv. Browse more head-to-heads on /compare, or see the top-ranked free tiers on /top.