Identify an iPhone or iPad using Microsoft Exchange
View the Exchange identifier
Users can see the unique device identifier called the Exchange Device ID, which is recognized by Exchange. A user can supply this identifier to you so that the device can be approved and allowed access to Exchange services. The Exchange Device ID changes only if the device is restored to factory settings. To view the Exchange Device ID on an iOS or iPadOS device, go to Settings > Passwords & Accounts > Add Account > tap Exchange.
Identify iOS versions
When an iOS or iPadOS device connects to a Microsoft Exchange Server, the device reports the iOS or iPadOS version. The version number is sent in the User Agent field of the request header, and it looks like this: Apple-iPhone2C1/705.018. The number after the delimiter (/) is the build number, which is unique to each release.
To view the build number on a device, go to Settings > General > About. The version number and build number are expressed like this: 4.1 (8B117A). The number in parentheses is the build number, which identifies the release the device is running.
When the build number is sent to the Exchange Server, it’s converted from the format NANNNA (where N is numeric and A is an alphabetic character) to the Exchange format NNN.NNN. Numeric values are retained, but letters are converted to their position value in the alphabet. For example, “F” is converted to “06” because it’s the sixth letter in the alphabet. Numbers are padded with zeros if necessary, to fit the Exchange format. For example, the build number 7E18 would be converted to “705.018.”
The first number, 7, remains as “7.” The character “E” is the fifth letter in the alphabet so it’s converted to “05.” A period (.) is inserted in the converted version, as required by the format. The next number,18, is padded with zero and converted to “018.”
If the build number ends with a letter, such as in 5H11A, the number is converted as described above, and the numeric value of the final character is appended to the string, separated by 3 zeroes. So 5H11A becomes “508.01100001.”