Soft matching user identifiers

One or more computer-readable non-transitory storage media embodying software that is operable when executed to:

• receive a bounce-back message corresponding to an initial message sent to a device, wherein the bounce-back message includes a copy of a token stored on the device, and wherein the token is indicative of a user of a system;
• identify a corresponding account for the user in the system based on the token;
• and
• update the corresponding account with information about the device.

A system comprising:

• one or more processors;
• and
• a memory coupled to the processors comprising instructions executable by the processors, the processors operable when executing the instructions to:
• receive a bounce-back message corresponding to an initial message sent to a device, wherein the bounce-back message includes a copy of a token stored on the device, and wherein the token is indicative of a user of a system;
• identify a corresponding account for the user in the system based on the token;
• and
• update the corresponding account with information about the device.