I created an email queue where I put the requests for emails to be sent. If the SMTP server is unavailable, the requests are not lost.

When the SMTP server gets back online, the background service will pick up the requests to send the emails and process accordingly.

Question: I now have a requirement to deliver text messages with high certainty, but also to give feedback about a wrong phone number if that is possible. Should I have something like my mail queue to send text messages to my user phones or not?

I think it makes sense if we're talking about marketing messages, but what about text messages sent to users to verify their phone numbers?

What if their phone number is typed incorrectly? The phone API will tell me right away but if I put the request in the queue, I won't be able to let them know about it.

Rephrasing of the question: Should I care about the immediate feedback and loose the ability to deliver all SMS messages in case of temporary failure?


Question: Show Windows 7 logon time?
Answer: I had the same issue for a network PC and this gave me results I was looking for:

wmic netlogin get name, fullname, lastlogon


...this will provide info for all users that have logged in.