Migrate from Infomaniak, Hostpoint or cyon
Move an app that sends through a hosted mailbox to smtp.letr.dev, with the hosters' sending limits, the settings to change and the first week.
Many apps send their mail through the SMTP server of a mailbox at their hoster. That works until the volume meets the mailbox's sending limit. letr.dev's SMTP relay takes the same kind of settings, with an API key as the password.
The hosters' limits
| Hoster | Sending limit as published |
|---|---|
| Infomaniak | 200 or 500 emails in 24 hours, depending on the product, for example 200 with kSuite Free and 500 with Mail Service Premium. The window rolls and is not reset at midnight (FAQ, 01.11.2026). |
| Hostpoint | We found no limit on its current support pages on 01.11.2026. Its control panel manual of January 2016 states 1'000 emails per address in 24 hours (manual, 2016). |
| cyon | 100 emails an hour per email account by default, up to 4'000 depending on the hosting product, in a blog post of 14.08.2018 (blog). |
For sending to many recipients, Infomaniak points to its own newsletter tool (same FAQ, 01.11.2026). In a comment under its 2018 blog post, cyon advised a specialised email provider for very large sendings. Ask your hoster for the current limit of your mailbox.
SMTP settings
A mailbox uses your hoster's server, for example mail.infomaniak.com on port 587 with STARTTLS or 465 with TLS, with the full mailbox address and its password (Infomaniak's protocol FAQ, 01.11.2026). letr.dev uses:
| Setting | Value |
|---|---|
| Host | smtp.letr.dev |
| Port | 587 with STARTTLS (required) or 465 with implicit TLS |
| Username | letr |
| Password | An API key with sending_access |
At Infomaniak and Hostpoint the ports are the same, so most apps change only the host, the username and the password; at cyon, check the ports of your mailbox. The from-address must be on a domain verified at letr.dev. The SMTP guide shows the settings for Django, Rails, WordPress and others.
Use one API key per app, so you can roll or revoke one without touching the others, and the mailbox password no longer sits in the app's configuration.
The first week
Your account goes live on payment and starts on step 0 with 50 recipients a day; it moves up to 500, then 2'000 and after the first paid renewal to no daily limit (limits). Past the daily limit the relay answers 451 4.7.1, a temporary code most SMTP clients retry later. The plan includes 10'000 recipients a month, and your monthly ceiling of 10'000 or 25'000 recipients applies throughout. Move an app that sends more than 50 a day once the account has reached a step that fits, or keep the mailbox for the rest until then.
DNS records
First add your sending domain in the dashboard, then publish letr.dev's DKIM record, a TXT record at letr._domainkey of your domain (DNS records). Your MX records, your SPF record and the mailbox stay as they are: bounces return to bounces.letr.dev, and replies still reach your mailbox.
What you gain
- Every email gets webhook events:
email.delivered,email.bounced,email.complainedand more. - A hard bounce or a complaint puts the address on the suppression list, and letr.dev stops sending to it.
- The dashboard shows each email and its events for 30 days, or 365 days with the add-on.
What letr.dev does not do
- Receiving email: letr.dev only sends, with no inbox and no IMAP. Keep the mailbox at your hoster for incoming mail.
- Newsletters and campaigns: letr.dev sends transactional email only.
- Open and click tracking.
- Sending from an unverified domain: the from-domain must be verified at letr.dev.
The plan costs CHF 12 a month for 10'000 recipients, then CHF 0.50 per started 1'000 recipients over. letr.dev counts per recipient: an email to three people counts three (overage).