UiPath.Mail.ExchangeException: Cannot get single emails from mailbox

Hi All,
I have browsed the forum on this issue a bit, but could not find a real answer or solution.

I am using the Get Exchange Mails activity to retrieve a list of emails from a mailbox. This works absolutely fine for 99% of the emails. However, some emails lead to the following error:

Exception Type: System.AggregateException

An ExceptionDetail, likely created by IncludeExceptionDetailInFaults=true, whose value is:
System.AggregateException: One or more errors occurred. ----> UiPath.Mail.ExchangeException: The specified string is not in the form required for an e-mail address. ----> System.FormatException: The specified string is not in the form required for an e-mail address.

As this only happens for single emails, I doubt that this has something to do with the activity settings or mailaccount information (as the 99% are working well).

I checked the last two emails that could not be processed. They have the following format:

As especially the first email format is completely normal, I am wondering what the issue could be.

Any pointers or help are greatly appreciated!


Hi @JoUt,
Welcome to the Community!
Are those mails the mailbox sending error reports or some kind of announcements maybe? I know that there is a problem with such elements and it’s even difficult to maintain using C++ or C# code.

Hi @Pablito,
Thank you for the welcome and thank you for the reply!

The emails in question are “normal” emails, sent by colleagues directly to the mailbox that I am trying to use in the automation. They are not announcements or error reports. As I am running the automation daily, I will check if there are any other new cases and if a pattern is visible. So far I cannot see it.

Any other option or explanation is still very welcome!

Best regards


I am running into the same issues using the Get Exchange Mail Messages activity. I can verify that it is not a setting issue and that I can connect to the exchange server as it works most of the time. However, if I try to send an email to the inbox using my email address or use outlook to edit one of the email messages, it doesn’t like the email anymore.

I have been getting a mess of errors:
The email is not in the store
One or more errors occurred
The specified string is not in the form required for an e-mail address.

I have noticed quite a few different threads talking about these issues, but I haven’t really seen any offer a fix beyond double-checking the parameters.

I am currently using
Orchestrator/Studio: 2019.4.3
UiPath Mail Activities: 1.4.1

I can add also that in one of the topic we observed that iOS devices are sending mails with completely different structure. This reminds me that you could save both mails… the working one and the other as a plain text or other format readable in notepad and compare it’s structure. Maybe there is something wrong or different.