Why do two objects appear to have the same ID?

Answer:

For certain email providers, object IDs (including messages and event IDs) are case-sensitive, meaning that even a single character difference in capitalization creates a completely different identifier. This can sometimes cause confusion when visually comparing event IDs.

Provider-Specific Case Sensitivity

Not all email providers handle object IDs the same way. Some providers, particularly Microsoft Exchange/Outlook, generate case-sensitive IDs where uppercase and lowercase letters are treated as distinct characters. This means what appears to be the same ID may actually reference different objects.

Example with Microsoft Provider

• Consider these two event IDs from a Microsoft calendar:

  • Event 1: AAMkADAwATM0MDAAMS1iNTkwLTI2MTUtMDACLTAwCgBGAAAAAAAiQ8W967B7TKBjgx9rVEURBwAiIsqMbYjsT5e-T-KzowKTAAAAAAENAAA
  • Event 2: AAMkADAwATM0MDAAMS1iNTkwLTI2MTUtMDACLTAwCgBGAAAAAAAiQ8W967B7TKBjgx9rVEURBwAiIsqMbYjsT5e-T-KzowKTAAAAAAeNAAA

   

  At first glance, these IDs look identical. However, the key difference is in the final characters:

  • Event 1 ends with: ENAA (uppercase 'E')
  • Event 2 ends with: eNAA (lowercase 'e')

   

This single character difference means these are two completely separate events.

Best Practices for Object ID Comparison

When working with object IDs from any provider:

1. Always perform case-sensitive string comparisons when checking if two IDs are the same
2. Avoid visual inspection for ID comparison, as subtle case differences can be easily missed
3. Log complete IDs to avoid truncation that might hide important differences
4. Be aware that case sensitivity behavior may vary between different email providers

Troubleshooting Apparent Duplicate Objects

If you believe you're seeing duplicate objects:

1. Verify the complete object IDs using case-sensitive comparison
2. Check object details like timestamps, content, and metadata to distinguish them
3. Review your API calls to ensure you're not inadvertently modifying existing objects

Object IDs are designed to be unique, so true duplicates should not occur under normal circumstances.

Updated June 10, 2025 17:50