Attachment limit properties
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Summary of Attachment limit properties
This documentation explains the properties in ServiceNow Yokohama release that control limits on email attachments for both inbound and outbound emails. These properties help manage the number and total size of attachments to maintain system performance and email deliverability.
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All attachment-related properties reside in the System Property [sysproperties] table, and you can review all email attachments in the Email Attachments [sysemailattachment] table.
Key Properties and Their Use
- glide.email.inbound.maxattachmentcount: Sets the maximum number of attachments allowed per inbound email (default 30).
- glide.email.inbound.maxtotalattachmentsizebytes: Sets the maximum combined size in bytes allowed per inbound email (default 18,874,368 bytes).
- glide.email.outbound.maxattachmentcount: Sets the maximum number of attachments allowed per outbound email (default 30).
- glide.email.outbound.maxtotalattachmentsizebytes: Sets the maximum combined size in bytes allowed per outbound email (default 18,874,368 bytes). This value should be set below the maximum email size due to encoding overhead during sending.
Note: The property com.glide.attachment.maxsize sets the maximum file size for any attachment in the system and overrides larger values set for inbound or outbound total attachment size.
Inbound Email Attachment Handling
- The system enforces the maximum number and total size of inbound email attachments based on the relevant properties.
- Attachments exceeding these limits are discarded, with a record created in the Email Attachments [sysemailattachment] table specifying the discarded file name and reason.
- The original email record retains the discarded file reference.
- The discard order may vary and is not guaranteed to be consistent.
- An event inbound.emailattachments.discarded is fired when attachments are discarded, which you can use to trigger notifications to alert senders.
- Duplicate attachments on inbound emails are prevented from attaching to the target record.
Outbound Email Attachment Handling
- The system enforces outbound email attachment count and size limits based on the corresponding properties.
- Emails exceeding these limits trigger warnings in the email system log and are sent with attachments only up to the configured maximums.
- This applies to emails generated from notifications, scheduled reports, and exports.
- If notification attachments exceed limits, excess attachments are excluded and a warning is logged.
- Large scheduled report attachments exceeding limits are omitted, and links to reports are recommended instead.
- For exported record lists emailed as attachments, if size limits are exceeded, the email is sent without the attachment and a warning is logged.
Implications for ServiceNow Customers
Understanding and configuring these properties allows you to control resource usage and prevent performance degradation caused by large or numerous email attachments.
Properly setting these limits ensures that inbound emails with attachments are processed reliably and outbound emails comply with size constraints, avoiding delivery issues.
Utilizing the discard event and system logs helps implement proactive notifications and troubleshooting around attachment handling.
Several properties control email attachment limits.
To see the status of all email attachments, go to the Email Attachments [sys_email_attachment] table.
Properties
All the properties are located in the System Property [sys_properties] table. Setting any of the following properties to an excessively large value may cause performance issues.
| Name | Description |
|---|---|
| glide.email.inbound.max_attachment_count | Sets the maximum number of attachments allowed per inbound email.
|
| glide.email.inbound.max_total_attachment_size_bytes | Sets the maximum total attachment size in bytes allowed per inbound email.
|
| glide.email.outbound.max_attachment_count | Sets the maximum number of attachments allowed per outbound email.
|
| glide.email.outbound.max_total_attachment_size_bytes | Sets the maximum total attachment size in bytes allowed per outbound email.
To send an email, the system must encode the contents of the email. This process
may significantly increase the size of the email, including any attachments. It is
best to set this property to a value well below the maximum email size.
|
Inbound email attachment processing
For inbound emails, the system enforces the maximum number and size of attachments as set by the glide.email.inbound.max_attachment_count and glide.email.inbound.max_total_attachment_size_bytes properties. When an attachment for an inbound email exceeds either value, the attachment is discarded. A record is created in the Email Attachments [sys_email_attachment] table containing the discarded file name and the reason it was discarded. The discarded file remains in the Email [sys_email] record. The order in which the system processes the attachments determines which attachments are discarded. This order may not be consistent from email to email.
When an inbound email attachment is discarded, the system also fires the inbound.email_attachments.discarded event. You can use the event to trigger a notification that alerts the email sender. For an example of a notification that can be triggered by the event, see the inactive "Demo Email Attachment(s) Discarded" notification.
Inbound email attachments are prevented from attaching to the target record if an identical attachment exists.
Outbound email attachment processing
For outbound emails, the system enforces the maximum number and size of attachments as set by the glide.email.outbound.max_attachment_count and glide.email.outbound.max_total_attachment_size_bytes properties. Email records are created from various sources and may exceed the configured attachment limits.
Emails that are ready to be sent from the Email [sys_email] table are subject to the outbound attachment limits. Emails that exceed either limit trigger a warning in the email system log and are sent with attachments up to the maximum number or total file size.
The log message for such an email might look like this: Maximum combined attachment size exceeded. (max:15728640 bytes). One or more attachment records ignored.
Emails for notifications, scheduled reports, and exported tables
Notifications can be set to include all the attachments from the record that triggers the notification. If the attachments exceed either of the outbound email attachment limits, the system excludes the excess attachments from the email and logs a warning message.
Reports can be scheduled for email distribution as attachments. Large reports may exceed the outbound attachment size limit. In this case, the system sends the scheduled report email without the report attached and logs a warning message. To avoid the issue, send links to large reports instead of sending the reports as attachments.
If a user attempts to export numerous records from a list that exceeds a configured warning threshold, a dialog box offers the option to email the exported records as an attachment. If the attachment exceeds the outbound attachment size limit, the system sends the email without the exported record list attached and logs a warning message.