[Outlook] Document attachment APIs (#5093)

* Add applicable attachment APIs

* Update ms.date

Author: samantharamon

docs/outlook/limits-for-activation-and-javascript-api-for-outlook-add-ins.md

@@ -1,7 +1,7 @@
 ---
 title: Limits for activation and API usage in Outlook add-ins
 description: Be aware of certain activation and API usage guidelines, and implement your add-ins to stay within these limits.
-ms.date: 02/11/2025
+ms.date: 03/25/2025
 ms.topic: best-practice
 ms.localizationpriority: medium
 ---
@@ -37,11 +37,11 @@ Each Outlook client enforces certain limits in the JavaScript object model, as d
 |Display the body of an existing item|32 KB number of characters|[Mailbox.displayAppointmentForm](/javascript/api/outlook/office.mailbox#outlook-office-mailbox-displaynewappointmentform-member(1)) method<br/><br/>[Mailbox.displayMessageForm](/javascript/api/outlook/office.mailbox#outlook-office-mailbox-displaymessageform-member(1)) method|For Outlook on the web, mobile devices, and [new Outlook on Windows](https://support.microsoft.com/office/656bb8d9-5a60-49b2-a98b-ba7822bc7627): limit for the body in an existing appointment or message form.|
 |Set the body|1 MB number of characters|[Body.prependAsync](/javascript/api/outlook/office.body#outlook-office-body-prependasync-member(1)) method<br/><br/>[Body.setAsync](/javascript/api/outlook/office.body#outlook-office-body-setasync-member(1))<br/><br/>[Body.setSelectedDataAsync](/javascript/api/outlook/office.body#outlook-office-body-setselecteddataasync-member(1)) method<br/><br/>[DisplayedBody.setAsync](/javascript/api/outlook/office.displayedbody?view=outlook-js-preview&preserve-view=true#outlook-office-displayedbody-setasync-member(1)) (preview)|Limit for setting the body of an appointment or message item.|
 |Set the signature|30,000 characters|[Body.setSignatureAsync](/javascript/api/outlook/office.body#outlook-office-body-setsignatureasync-member(1)) method|Limit for the length of a signature in an appointment or message.|
-|Number of attachments|499 files in Outlook on the web and [new Outlook on Windows](https://support.microsoft.com/office/656bb8d9-5a60-49b2-a98b-ba7822bc7627)|[Item.addFileAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method|Limit for the number of files that can be attached to an item for sending. Outlook on the web and [new Outlook on Windows](https://support.microsoft.com/office/656bb8d9-5a60-49b2-a98b-ba7822bc7627) generally limit attaching up to 499 files through the user interface and `addFileAttachmentAsync` method. Outlook on Windows (classic) and on Mac don't specifically limit the number of file attachments. However, all Outlook clients observe the limit for the size of attachments (see the "Size of attachments" row in this table).|
-|Size of attachments|Dependent on Exchange Server in classic Outlook on Windows and Outlook on Mac<br/><br/>25 MB in Outlook on the web and new Outlook on Windows|[Item.addFileAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method|Limit for the size of all the attachments added to a mail item. In classic Outlook on Windows and Outlook on Mac, the limit is configured by an administrator on the Exchange Server of the user's mailbox. In these clients, this also limits the number of attachments of an item. For Outlook on the web and [new Outlook on Windows](https://support.microsoft.com/office/656bb8d9-5a60-49b2-a98b-ba7822bc7627), the lesser of the two limits—the number of attachments and the size of all attachments—restricts the actual attachments of an item.|
-|Attachment filename|255 characters|[Item.addFileAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method|Limit for the length of the filename of an attachment to be added to an item.|
-|Attachment URI|2,048 characters|[Item.addFileAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method<br/><br/>[Item.addFileAttachmentFromBase64Async](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method|Limit of the URI of the filename to be added as an attachment to an item.|
-|Base64-encoded string of an attachment|27,892,122 characters (about 25 MB)|[Item.addFileAttachmentFromBase64Async](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method|Limit of the Base64-encoded string to be added as an attachment to an item.|
+|Number of attachments|499 files in Outlook on the web and [new Outlook on Windows](https://support.microsoft.com/office/656bb8d9-5a60-49b2-a98b-ba7822bc7627)|[Item.addFileAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method<br/><br/>[ReplyFormData.attachments](/javascript/api/outlook/office.replyformdata#outlook-office-replyformdata-attachments-member)|Limit for the number of files that can be attached to an item for sending. Outlook on the web and [new Outlook on Windows](https://support.microsoft.com/office/656bb8d9-5a60-49b2-a98b-ba7822bc7627) generally limit attaching up to 499 files through the user interface and `addFileAttachmentAsync` method. Outlook on Windows (classic) and on Mac don't specifically limit the number of file attachments. However, all Outlook clients observe the limit for the size of attachments (see the "Size of attachments" row in this table).|
+|Size of attachments|Dependent on Exchange Server in classic Outlook on Windows and Outlook on Mac<br/><br/>25 MB in Outlook on the web and new Outlook on Windows|[Item.addFileAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method<br/><br/>[ReplyFormData.attachments](/javascript/api/outlook/office.replyformdata#outlook-office-replyformdata-attachments-member)|Limit for the size of all the attachments added to a mail item. In classic Outlook on Windows and Outlook on Mac, the limit is configured by an administrator on the Exchange Server of the user's mailbox. In these clients, this also limits the number of attachments of an item. For Outlook on the web and [new Outlook on Windows](https://support.microsoft.com/office/656bb8d9-5a60-49b2-a98b-ba7822bc7627), the lesser of the two limits—the number of attachments and the size of all attachments—restricts the actual attachments of an item.|
+|Attachment filename|255 characters|[Item.addFileAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method<br/><br/>[ReplyFormAttachment.name](/javascript/api/outlook/office.replyformattachment#outlook-office-replyformattachment-name-member)|Limit for the length of the filename of an attachment to be added to an item.|
+|Attachment URI|2,048 characters|[Item.addFileAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method<br/><br/>[Item.addFileAttachmentFromBase64Async](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method<br/><br/>[ReplyFormData.url](/javascript/api/outlook/office.replyformattachment)|Limit of the URI of the filename to be added as an attachment to an item.|
+|Base64-encoded string of an attachment|27,892,122 characters (about 25 MB)|[Item.addFileAttachmentFromBase64Async](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method<br/><br/>[ReplyFormAttachment.base64file](/javascript/api/outlook/office.replyformattachment#outlook-office-replyformattachment-base64file-member)|Limit of the Base64-encoded string to be added as an attachment to an item.|
 |Attachment ID|100 characters|[Item.addItemAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method<br/><br/>[Item.removeAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method|Limit for the length of the ID of the attachment to be added to or removed from an item.|
 |Asynchronous calls|3 calls|[Item.addFileAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method<br/><br/>[Item.addItemAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method<br/><br/>[Item.removeAttachmentAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method<br/><br/>[Body.getTypeAsync](/javascript/api/outlook/office.body#outlook-office-body-gettypeasync-member(1)) method<br/><br/>[Body.prependAsync](/javascript/api/outlook/office.body#outlook-office-body-prependasync-member(1)) method<br/><br/>[Body.setSelectedDataAsync](/javascript/api/outlook/office.body#outlook-office-body-setselecteddataasync-member(1)) method<br/><br/>[CustomProperties.saveAsync](/javascript/api/outlook/office.customproperties#outlook-office-customproperties-saveasync-member(1)) method<br/><br/>[Item.LoadCustomPropertiesAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox.item#methods) method<br/><br/>[Location.getAsync](/javascript/api/outlook/office.location#outlook-office-location-getasync-member(1)) method<br/><br/>[Location.setAsync](/javascript/api/outlook/office.location#outlook-office-location-setasync-member(1)) method<br/><br/>[Mailbox.getCallbackTokenAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox#methods) method<br/><br/>[Mailbox.getUserIdentityTokenAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox#methods) method<br/><br/>[Mailbox.makeEwsRequestAsync](/javascript/api/requirement-sets/outlook/preview-requirement-set/office.context.mailbox#methods) method<br/><br/>[Recipients.addAsync](/javascript/api/outlook/office.recipients#outlook-office-recipients-addasync-member(1)) method<br/><br/>[Recipients.getAsync](/javascript/api/outlook/office.recipients#outlook-office-recipients-getasync-member(1)) method<br/><br/>[Recipients.setAsync](/javascript/api/outlook/office.recipients#outlook-office-recipients-setasync-member(1)) method<br/><br/>[RoamingSettings.saveAsync](/javascript/api/outlook/office.roamingsettings#outlook-office-roamingsettings-saveasync-member(1)) method<br/><br/>[Subject.getAsync](/javascript/api/outlook/office.subject#outlook-office-subject-getasync-member(1)) method<br/><br/>[Subject.setAsync](/javascript/api/outlook/office.subject#outlook-office-subject-setasync-member(1)) method<br/><br/>[Time.getAsync](/javascript/api/outlook/office.time#outlook-office-time-getasync-member(1)) method<br/><br/>[Time.setAsync](/javascript/api/outlook/office.time#outlook-office-time-setasync-member(1)) method|For Outlook on the web and on mobile devices, and [new Outlook on Windows](https://support.microsoft.com/office/656bb8d9-5a60-49b2-a98b-ba7822bc7627): limit of the number of simultaneous asynchronous calls at any one time, as browsers allow only a limited number of asynchronous calls to servers. |
 |Append-on-send|5,000 characters|[Body.appendOnSendAsync](/javascript/api/outlook/office.body#outlook-office-body-appendonsendasync-member(1)) method|Limit of the content to be appended to a message or appointment body on send.|