"Plus Addressing" is a quick way to create unique email addresses and is supported and allowed by many email services such as Gmail and Microsoft. The special character + is allowed/supported in the various standards for email.
As a partner, we are managing all of the API accounts for our customers. As a business that uses Google as our infrastructure, we are charged per mailbox we create and/or have a limit on how many alias addresses we can associate with a mailbox. There is not, however, a limit on "plus addressing". For example, with no setup from me, any of the following email addresses will delivery mail to my inbox: jmcgimsey+SES@ourdomain.com, jmcgimsey+ky_lab@ourdomain.com, jmcgimsey+MessageFromChristoph@ourdomain.com, etc. It is a handy way to manage a personal mailbox but especially so when using a shared/common mailbox, with no additional setup or maintenance required.
In our case, I'd wanted to use our common "support" mailbox, support@ky.ourdomain.com. I'd planned to use plus addressing to create the API accounts for our lab (i.e. support+ky_lab@ky.ourdomain.com) and each of the stores we install/support. Since plus addressing did not work, I had to get an administrator to create an alias addresses to the support@ky.ourdomain.com (i.e. ses_storename@ky.ourdomain.com). The issue with that is that only 30 aliases are allowed per mailbox. There is one group of people that monitor that support mailbox and will be supporting all our sites. Somehow, I'll have to manage getting all alerts, notifications, etc. funneled into that mailbox as our client base grows. Plus addressing makes that simple and clean.
In setting up our first store, I got so far as being able to create the API account and receive the verification email, but clicking the link on the verify got me to an "Error Request not found" page.
Dear customer,
Thank you for your idea. Unfortunately today we don't plan to allow the "plus addressing" for API accounts.
Best,
Emmanuelle