> For the complete documentation index, see [llms.txt](https://docs.sendman.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sendman.com/admin-portal/sendman/smtp-credentials.md).
# SMTP Credentials
Manage the usernames and passwords your clients sign in to Sendman with
## Overview
**SMTP credentials** are usernames and passwords that are managed in Sendman. Mail clients, devices and applications use them to sign in to Sendman. In [authorization policies](/admin-portal/sendman/authorization-policies.md), they appear under the identity provider **Sendman**.
{% hint style="info" %}
A credential only takes effect once an [authorization policy](/admin-portal/sendman/authorization-policies.md) references its username. A client that signs in successfully but is not covered by a policy cannot send.
{% endhint %}
Use SMTP credentials when:
* the client cannot sign in with a Microsoft Entra ID account,
* the client uses **AUTH NTLM**, which Sendman only supports with SMTP credentials, or
* you want a separate credential per device or application that you can revoke individually.
## Add
1. Click **Add credential**.
2. Enter a **Username**, up to 100 characters. Letters, digits and the characters `. - _ @ / \` are allowed, e.g. `scanner-hq` or `scanner@contoso.com`.
3. Enter the **Password** and repeat it under **Confirm password**.
4. Optionally, enter a **Description**, e.g. the location of the device.
5. Save the credential.
{% hint style="warning" %}
The username cannot be changed after creation. Passwords are stored encrypted and cannot be displayed again, so note the password before you close the dialog.
{% endhint %}
## Change the password
1. Click the edit icon of the credential.
2. Enter the **New password** and confirm it. Leave the fields empty to keep the current password and only change the description.
3. Save the credential.
Clients that are already connected keep their session; the new password is required for the next sign-in.
## Delete
Click the delete icon of the credential and confirm. Clients using it can no longer sign in. Authorization policies that reference the username are kept, but no longer match any client.
---
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