Sending services
A sending service is a company whose whole job is delivering email that programs send: password resets, receipts, notifications. You give Tesria the service’s SMTP details, and the service does the delivering, from an address on your own domain, such as wiki@yourcompany.com.
Why use one instead of a Gmail or Outlook account? They are built for it, so they do not have a person’s daily sending limits, their mail is less likely to land in spam, and nobody’s own mailbox is tied to the wiki. Most are free, or cost a few dollars a month, at a small team’s volume.
What they all have in common
You prove the domain is yours. The service gives you a few records to add to your domain’s DNS, where your domain is registered. Until they check out, it sends little or nothing. Some let you verify a single address instead, by clicking a link sent to it.
You make SMTP credentials, a username and password (or key) for sending, separate from your account’s password. Most show the password only once.
You fill them in Tesria. In Admin, Settings, Email, choose the service under Provider, which fills in the server, then add the credentials and a From address on your domain. See Email (SMTP).
Free tiers change. What each offers for free was checked on September 24, 2026. Look at the service’s pricing page before you decide.
Amazon SES
Amazon’s service, and the cheapest at volume. It suits you if you already use AWS; its setup is the most involved.
Free to start: no free sending of its own; new AWS accounts get credits that cover it for a while. A new account starts in a “sandbox” that sends only to addresses you have verified, up to 200 a day, until you ask AWS for production access.
Credentials: in the SES console, under SMTP settings, choose Create SMTP credentials. They are not your AWS access keys, they belong to one AWS region, and the password is shown once.
Before it sends: verify your domain (three DNS records) or single addresses, in the same region.
Setting | Value |
|---|---|
Provider | Amazon SES |
SMTP host |
|
Port |
|
Encryption | STARTTLS |
Username | The SMTP username from SES’s SMTP settings (not your AWS access key) |
Password | The SMTP password shown with it, once |
From address | An address on your verified domain |
Postmark
Known for fast, reliable delivery of exactly this kind of email.
Free to start: 100 emails a month on its developer plan, which does not expire. Until Postmark approves the account, it sends only to addresses on your own verified domain.
Credentials: the server’s API token works as both username and password; or make an SMTP token under the message stream’s settings.
Before it sends: verify your domain, or a sender signature for one address.
Setting | Value |
|---|---|
Provider | Postmark |
SMTP host |
|
Port |
|
Encryption | STARTTLS |
Username | The server’s API token (or an SMTP token’s access key) |
Password | The same API token (or the SMTP token’s secret key) |
From address | An address on your verified domain |
Mailgun
A long-standing service with a free plan and US and EU regions.
Free to start: a small free plan; check Mailgun’s pricing page for its current limits. Its test (“sandbox”) domain sends only to up to five addresses you authorize.
Credentials: under Send, Sending, Domain settings, the SMTP credentials tab, for each domain. A new password is shown once.
Before it sends: verify your domain with its DNS records. A domain in the EU region uses the EU server, smtp.eu.mailgun.org.
Setting | Value |
|---|---|
Provider | Mailgun |
SMTP host |
|
Port |
|
Encryption | STARTTLS |
Username | The full SMTP login for your domain, such as name@mg.example.com |
Password | That login’s SMTP password, from the domain’s SMTP credentials |
From address | An address on your verified domain |
SendGrid
Twilio’s service, widely used.
Free to start: a trial of 100 emails a day for 60 days; after that it is paid.
Credentials: the username is the word apikey, exactly, and the password is an API key with Mail Send permission, made under Settings, API Keys. The key is shown once.
Before it sends: verify a single sender address, or authenticate your domain.
Setting | Value |
|---|---|
Provider | SendGrid |
SMTP host |
|
Port |
|
Encryption | STARTTLS |
Username | The word apikey, exactly |
Password | An API key with Mail Send permission |
From address | An address on your verified domain |
Brevo
A European service that also does newsletters.
Free to start: up to 300 emails a day, once Brevo has approved the account for sending.
Credentials: on the SMTP tab of its SMTP and API settings: your SMTP login, and an SMTP key (not an API key).
Before it sends: add and verify a sender, or authenticate your domain.
Setting | Value |
|---|---|
Provider | Brevo |
SMTP host |
|
Port |
|
Encryption | STARTTLS |
Username | Your SMTP login, from Brevo’s SMTP settings |
Password | An SMTP key (not an API key) |
From address | An address on your verified domain |
Resend
A newer service with a generous free plan.
Free to start: 3,000 emails a month, up to 100 a day.
Credentials: the username is the word resend, exactly, and the password is an API key from its API Keys page, shown once.
Before it sends: verify your domain; until then it sends only to your own address.
Setting | Value |
|---|---|
Provider | Resend |
SMTP host |
|
Port |
|
Encryption | STARTTLS |
Username | The word resend, exactly |
Password | An API key |
From address | An address on your verified domain |
SMTP2GO
A simple relay with a free plan that does not run out.
Free to start: 1,000 emails a month, up to 200 a day. It asks for a work email address to sign up.
Credentials: under Sending, SMTP Users.
Before it sends: add a verified sender domain (or a single address) under Sending, Verified Senders.
Setting | Value |
|---|---|
Provider | SMTP2GO |
SMTP host |
|
Port |
|
Encryption | STARTTLS |
Username | An SMTP user’s username, from Sending, SMTP Users |
Password | That SMTP user’s password |
From address | An address on your verified domain |
Applies to | Tesria 0.5 and later |
|---|---|
Updated | September 24, 2026 |
Changes | Revised. |