Email Handling

How to handle incoming Email tasks

Nimbus services handle Email tasks within their regular queue within the My Sessions view.


  • Contact Center Note that Email is an additionally per-user enabled modality. Refer to Use Case - Setting Up Email for technical details and setup.
  • Email Tasks require users to have Nimbus open in a browser in order to use My Sessions to display and reply to Email contents. Other areas of the Nimbus UI do not have sufficient space to render the mail contents, but will show the incoming task.

In the following example, a Nimbus user is notified about an incoming Email task and handles it directly within My Sessions.

🔎 Same as in other tasks, Nimbus can open Conversation Context URLs, or simply display System Fields and Parameters within My Sessions > Session details widget. For simplicity's sake, we keep the attention only on the email-specific parts.

A user receiving (and accepting) an Email Task 

As the user accepts the email task, the My Sessions view will open an “Email” widget with a rendered preview of the Mail. The user can choose to: 

  • Reply / Reply All senders of the original Email.
  • Mark as handled (e.g. when just a read-confirmation or other actions are required).
Reply and handling options

💡Workflow relationship: The Email Workflow can contain a separate “Mark as handled” Workflow Activity, so replying does not necessarily mark the end of an Email task.

Note that other “user-invisible” activities can be configured via workflow, such as sending an automated message to the customer via “Reply” activity or including further concepts such as Opening Hours to differentiate the response or deflecting an email outright.


Email Editor

When opting to reply, the Email widget will show an editor.

Replying and managing Attachments with the Editor

Inside the editor, the users have access to HTML-Text-formatting options such as: 

  • Font, Font Size and Font Style formatting
  • Various list styles
  • Text alignment and orientation options
  • An option to clear formatting

Notes on the Editor

  • The editor will render embedded images and also show attachments, within the constraints shown in chapter “Email Attachments” below.
  • Replies will always be sent using the “From” mail address (UPN) of the mailbox. This field is locked to prevent tampering.

Email Attachments

INC Email Attachments

Attachment info shown

The following information will be shown for attachments:

  • Icons for known attachment File types
  • File Size
  • Name (cut off, fully visible on tooltip)

💡Larger amounts of attachments are shown as scrollable list.

Allowed attachments 

(file extensions and mime types)

Allowed known file extensions will be as follows:

  • Excel: [.xls, .xlsx]
  • OneNote: [.one, .onetoc2]
  • Outlook: [.pst, .ost, .msg, .oft, .nk2, .pab, .srs]
  • pdf: [.pdf, .pdfa, .pdfx, .pdfe, .pdf/vt]
  • PowerPoint: [.ppt, .pptx]Word: [.doc, .docx]
  • zip: [.zip, .rar, .tar, .7z, .tar.gz, .tgz, .tar.bz2, .tbz2, .tar.xz, .gz, .bz2, .xz]

Allowed known file mime-types are also identified:

  • audio: mime types starts with"audio/"
  • img: mime types starts with"image/"
  • txt: mime types starts with"text/"
  • video: mime types starts with"video/"

☝Attachment size and content checks: Nimbus follows your organizational settings. Refer to the FAQ notes below.

Blocked attachments

☝Note: Formats (as defined per 🔎 Microsoft Outlook - Blocked attachment list) will be prevented from upload. 

💡A popup will inform about the upload prevention.

☝Unknown attachments: check the FAQ notes below on what to do when existing attachments are not being shown.


Attachments FAQ and Troubleshooting

🤔What is the maximum size of attachments?

OUTGOING allowed file size for all combined attachments is limited to 20 MB  
🔎 As per Microsoft Docs > Exchange 2013 definition. Your local organizational limits set for the mailbox may deviate from this. 
💡A popup will inform when this limit is exceeded. 

INCOMING Email attachments have no size limits.


🤔Which attachment checks are performed?

No malicious / spam checks

Aside from displaying links and attachments for download, Nimbus does NOT perform any attachment filtering or checks for malicious files. 

✅ As mailbox owner/administrator you need to ensure that according filters and malware checks are applied on the mailbox before reaching the inbox folder.


🤔Why are (known) attachments not showing?

Unknown Attachment download prevention

If for any reason attachments cannot be shown / downloaded in Nimbus, a message will be shown instead, informing that the attachments should be checked directly in the mailbox.

✅ If you have encountered a use case of clearly non-malicious files which you expect to handle via the Nimbus UI please contact support so we can analyze your case and extend the list of allowed attachments.

INC Luware Support Address

 Luware Website
Luware Helpdesk 
Cloud Service Status
Luware support contact details





Email Tasks in other areas

Emails are also shown in other areas of Nimbus such as:

💡Good to know: As part of the default Task Queue and Distribution algorithm, email tasks are always automatically distributed to users, regardless on where they appear within Nimbus. Users cannot manually pick up an Email task like an incoming call, but can be set as preferred/most-skilled by using Distribution Policies and Skills and Responsibilities.


💡 Session Details and Context: By default, no service or user details will be part of the email body. Only the incoming service is shown to Nimbus users. 

✅ Any additional information or context for the email handling user has to come via “Session Details” widget (configured via Extensions Service Settings), with fields filled by the Nimbus Power Automate Connector, e.g. by identifying the incoming customer email address.


Known Limitations

INC Known Email Limitations


Please note the following design limitations of Email tasks: 

If for any reason the subscription to an Exchange mailbox is interrupted, removed or suspended (as indicated in the Modality Service Settings below the “Mailbox” pulldown), any mails received during this downtime will NOT be handled.

Status Message indicator below the Mailbox pulldown

🤔 Why is it handled like this?  This is a limitation by design. As the maximum tasks are limited by Tenant Settings it protects the Task Queue and Distribution from flooding with potentially stale and outdated tasks.

🤔 Which cases are handled? Any interruption to the Mailbox subscription caused on Nimbus side will result in Nimbus resuming the tasks where left of. 




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