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![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(115.19999999999999, 12%, 21%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EFF%3C/text%3E%3C/svg%3E)
As the screenshot I attached, the uid is a number, it is always a number for office365? or it has been changed before.
Hi @Frank Feng ,
Based on your description, I changed the tag to office-exchange-online-itpro, The reason why we recommend posting appropriately is you will get the most qualified pool of respondents, and other partners who read the forums regularly can either share their knowledge or learn from your interaction with us. Thank you for your understanding.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(252.8, 22%, 34%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ELL%3C/text%3E%3C/svg%3E)
Hi @Frank Feng ,
Since the screenshot you provided contains your personal privacy, I helped you to re-upload the screenshot after covering it
Oh, my mistake, thank you.
Hi @Frank Feng ,
According to my test in the lab environment, I did not see this attribute “uidOnServer”in the mail sent by Exchange. And according to my research, the uidOnserver is more related to Exchange development. I will change the tag of this post to a tag related to Exchange development. You will get more professional help. Hope this issue can be resolved as soon as possible.
Thanks for your understanding.
@Lucas Liu-MSFT Thanks.
Acctually, we are using a third party lib to poll emails with Pop3.
refer to: docs
It is the remarks from their document:
However, some old POP3 servers do not support UIDs, and thus this property will still return null if UIDs are not supported by the server.
So, I am not sure the Uid is provided by office365, or by Mailbee Lib.
Hi @Frank Feng ,
I noticed this during the research process, so I checked the email sent directly through Exchange in the test environment and found that there is no such parameter. Therefore, it is recommended that you contact the supplier of the third-party program to see if there is any relevant information.