Send Calendar Invite is not adding the attendees correctly


I’m using the Send Calendar Invite activity in UiPath. It creates the event, but, it doesn’t add the attendees emails. I was checking, and in the event on Outlook calendar the emails appear, but they display as incorrect email. However, they are written in a good way. Also, it only allows to add only one email. I’ve tried to separete them by “;”, but it didn’t work.

I’m using UiPath Studio 2023.2.0 and the Mail.Activities package is 1.18.2 v


Hi @alejandromendoza,

When using the Send Calendar Invite activity in UiPath to add attendees to an event, you should pass a string array with the email addresses of the attendees. Each email address should be separated by a comma, not a semicolon.

  1. Define an array variable to store the email addresses of the attendees. For example, you can define a variable named attendees of type String[] and initialize it with the email addresses:
attendees = {"", "", ""}
  1. Use the Send Calendar Invite activity to create the event and add the attendees. Set the Attendees property of the activity to the attendees variable,


I’ve tried the solution that you suggested. However, the input variable for the attendees must be a string. The string is not allowed

try this

ListMailAdd is String

Lakshmi Narayana


Using that solution I’m having the same problem for the attendees. They are still recognized in the event as wrong emails.

In the String[ ] variable there are three emails, however, only the first one is being added to the event, and is not recognized as email.

Please follow below steps.

  1. Add Excel Application Scope and Read the list of Email IDs and store them in a DataTable
  2. Required Attendees : Use this expression to add attendees name from a DataTable

[ String.Join(";"c, DT1 DataTable_Name.AsEnumerable().select(Function(x) x.Field(of String) (“Email ID” Column Name)).ToArray()) ]


Can you confirm if you are using use outlook app activity?

And did you try changing the version of mail packages and check?

I did test from my end and the invites are sent as well…I tested for multiple people with valid addresses and its working format used ";"…If we are giving wrong address also the activity still is moving ahead by we are getting a not delivered notification in email itself directly

Alternately delete the mail package from .nuget folder and reopen the project…it download the dependencies again…or go to manage packages and add again so that package is downloaded again
Location: C:\Users\<Username>\.nuget\packages


1 Like

Hi all,

Thank you so much for the help. I could fix the problem, the solution was change the version of the Mail.Activities package. I was using the 1.18.2 version, currently I’m using the 1.15.2, this one is the most recent that has worked.

However, is important to take into account that, for the more recents versions, the activity is not working as expected. I was using the activity Send Calendar Event inside a Use Outlook 365 card.

Regards! :robot: