What happens when you exceed the limit
Requests rejected once the daily allowance is used. Sending services enforce their quotas at the API, so the failure is explicit and immediate. The reputation of the domain you send from is a separate matter that the quota does not protect.
Where sender reputation sits on Mailgun
Mailgun has no mailbox to warm. It relays the mail your app or platform hands it. Reputation sits on your sending domain and the IP, and mailbox providers build it from what recipients do with your mail.
Seed lists for Mailgun senders
You pay for Mailgun, the list and the campaign whether anyone reads the mail or not. When Gmail files it in spam, it goes unread, and Mailgun still counts it as delivered.
MailStrike seed lists put real Gmail and Outlook inboxes on your recipient list. You add the seed addresses to your Mailgun send, and each seed inbox:
- opens the email and stays on it
- moves it out of spam or promotions into the inbox
- marks some of it important
Gmail and Outlook read that engagement when they decide where the rest of your mail goes. You also see where the real send landed in Gmail and Outlook: inbox, promotions or spam.
Use them two ways:
- Mixed into a send. The seeds go out with a real campaign and engage with it as it arrives, so the send carries good signals while it goes out.
- Sent to first. The campaign goes to the seeds before your list, so the content and the domain have engagement on record when the real send goes out.
Setup is a CSV of seed addresses you add to your recipient list like any other contacts, and one DNS TXT record. It works the same day, and seed lists are sold on their own.
Trial, free tier and new-account restrictions
100/day. Free and trial tiers exist to test integration, not to run campaigns; the volume above them is a plan decision.
The bulk sender rules are a separate limit
None of the caps above is the line that decides placement. Google's and Yahoo's bulk-sender requirements and Microsoft's 2025 high-volume rules set authentication, spam-rate and unsubscribe conditions that apply well below any sending cap; the sender requirements page has them provider by provider, and the auth checker tests a domain against them.
How Mailgun compares
documented cap per day (log scale); basis differs per provider
Questions about Mailgun sending limits
What is the Mailgun sending limit per day?
Free plan 100 messages/day, 1 domain. Recipients per day: plan-based. Source: Mailgun's own documentation, checked 6 Sep 2026.
What happens when you exceed the Mailgun sending limit?
Requests rejected once the daily allowance is used. Above the plan's allowance, sending resumes when the quota or plan allows.
How many recipients per message does Mailgun allow?
1,000 per API call.
How do I increase the Mailgun sending limit?
100/day. Volume above that is plan-based: Free plan 100 messages/day, 1 domain.
Is there a Mailgun rate limit per minute or per hour?
plan-based.
How do seed lists work with Mailgun?
You add MailStrike's seed addresses to your Mailgun send. Real Gmail and Outlook inboxes open the email, move it out of spam or promotions and mark some of it important, and Gmail and Outlook read that engagement when they place the rest of your mail. Setup is a CSV of seed addresses on your recipient list and one DNS TXT record.