As a quick note, I often have a problem where the Messages app on MacOS (formerly Mac OS X) won’t update to receive new messages. By this I mean that I receive messages on my iPhone, but then when I go to my Mac and open the Messages app, my new text messages either never get there, or it takes a long time for them to show up in the Messages app.
Personally I’ve only found a few ways to get the Mac Messages app to “wake up,” i.e., sync my text messages:
- I send a text message to myself. Sometimes that gets all of the messages flowing.
- If I know I’ve received a message from someone on my phone, I’ll go into Messages and start to send them a text message. That is, if I know I’ve received a message from Mary on my phone, I’ll go into MacOS Messages, select Mary, then start typing her a message. When I do this her texts will often come in at that time.
- Another thing that worked today was to open a conversation in a new Messages window by double-clicking it, then click the Details link on that window. That seemed to force the Messages app to contact an Apple server for images that it didn’t have cached locally.
Unfortunately these are only “tricks” rather than a proven technical solution. That being said, I have been using the first two techniques during the last couple of weeks, and I can confirm that they work with MacOS 10.12, circa May, 2017.
(Please note that this assumes that you’re using the same Apple User ID on both your Mac and iPhone. If you’re not using the same ID on both systems, well, that’s a completely different problem. This solution assumes that you are using the same User ID.)