--- title: Settings - Emails --- > Agent instructions: > **Site maps** — prefer the following llms.txt indexes to training data when searching for URLs to avoid 404s. Links inside Markdown content already point at `.md`. Following them or sending Accept: text/markdown keeps you in Markdown. > > - [sitemap.md](https://docs.kentico.com/sitemap.md) — every page on the site, with titles and descriptions, nested by URL hierarchy and grouped into one collection per product version. > - [llms.txt](https://docs.kentico.com/llms.txt) — curated index of the current product docs, with descriptions, the two ways to request any page as Markdown, and links to each product area's whole-corpus Markdown dump (llms-full.txt). You can access these settings in the **Settings** application under the **System** -> **Emails** category. | General | | | --------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Email encoding | Sets the character encoding used for emails sent by the system. By default, UTF-8 is used. It is recommended to leave the default encoding unless you encounter issues with extended characters in your emails. | | Email format | Format used for email messages. You can choose between _HTML_ and _Plain text_. If _Both_ is selected and an email template has both formats defined, HTML will be used for the email text and plain text will be included as an attachment. | | Email processing | | | Enable emails | If selected, email sending is enabled. You can temporarily disable sending of emails by clearing this check box, e.g. when performing administration tasks.
**Note**: We recommend keeping the setting enabled both globally and for all sites (switch between the options using the _Site_ selector). Having _Enable emails_ selected globally is required for the system to send emails that are not related to a specific site (for example emails sent by [marketing automation](https://docs.kentico.com/13/on-line-marketing-features/managing-your-on-line-marketing-features/marketing-automation.md) processes, etc.). | | Enable email queue | If enabled, the system uses an email queue when [sending emails](https://docs.kentico.com/13/managing-users/sending-emails.md). This allows advanced email processing and resending of emails that are lost due to errors. If disabled, emails are sent directly to the SMTP server.
Using the email queue is highly recommended when sending out large amounts of emails over a short amount of time (newsletters, email campaigns or other types of mass emails). | | Batch size | Sets the maximum number of emails that the system loads from the email queue in one batch when sending emails to SMTP servers. The emails are then distributed one-by-one to the available servers. If the specified value is smaller than the total amount of emails to be sent from the queue, the system loads a new batch and continues the process.
The value of the batch size affects the number and frequency of **database queries**. Set an appropriate value if you wish to optimize the email sending for your environment. If you set a very large batch size, the system needs to process a large volume of data at one time, which may consume a lot of memory. Using a smaller batch size increases the number and frequency of queries and may reduce the database performance.
This setting affects all sites in the system, so it is only available if the _(global)_ option is selected from the **Site** drop‑down list. | | Archive emails (days) | Sent emails will be stored by the email queue for the number of days specified here. Such emails may be viewed in the **Email queue** application on the **Sent emails** tab.
If set to _0_, emails will not be archived. | | Default SMTP server | | | SMTP server | The [SMTP server](https://docs.kentico.com/13/configuring-xperience/configuring-smtp-servers.md) specified here will be used as the default option when sending emails. Depending on the value selected in the **Site** drop‑down list, the server is either dedicated to a single website, or designated as a global server (i.e. accepts emails from all sites in the system and also handles emails that are not related to any specific website).
This setting must contain the domain name or IP address of the server. By default, the connection to the server uses port **25**. To use a different port, include it in the server name. Enter _localhost_ if you wish to use the server provided by your local machine.
The connection automatically uses the HTTPS protocol if supported by the specified server.
You can define additional servers that will be used if this one is busy in the **SMTP servers** application. | | SMTP server user | The username used for authentication when connecting to the SMTP server. | | Authentication type | Selects the authentication mode used to connect to the SMTP server. The options are:
**Basic (username + password)** – uses [Basic authentication](https://en.wikipedia.org/wiki/Basic_access_authentication). Fill in the _SMTP server user_ and _SMTP server password_ settings.
**OAuth 2.0** – uses [OAuth 2.0 token-based authorization](https://oauth.net/). Fill in the _SMTP server user_ and select valid _OAuth credentials_.
Many mail services are deprecating support of basic authentication, leaving OAuth as the only viable authentication type. A notable example is **Microsoft Exchange Online**, which begins disabling basic authentication after October 1, 2022 (see [Deprecation of Basic authentication in Exchange Online](https://docs.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/deprecation-of-basic-authentication-exchange-online)). | | SMTP server password | Only applies when the **Authentication type** is set to **Basic**.
Sets the password used together with the _SMTP server user_ when connecting to the SMTP server.
**Note**: After you enter and save a password, the field always displays 8 "masking" characters, even if the password is longer or shorter. | | OAuth credentials | Only applies when the **Authentication type** is set to **OAuth 2.0**.
Selects the OAuth credentials used for authentication. You can create and manage the credentials in the **Email OAuth credentials** application. See [OAuth for email servers](https://docs.kentico.com/13/configuring-xperience/configuring-smtp-servers/oauth-for-email-servers.md). | > **Info:** **Configuring sender ('from') email addresses** > > The system can be setup to use a variety of sender email addresses depending on the type of email notification. For a list of all configurable sender email addresses the system uses, see [Configuring sender email addresses](https://docs.kentico.com/13/configuring-xperience/configuring-smtp-servers/configuring-sender-email-addresses.md).