How-to: Make sure you keep receiving iMessage texts on your new phone
We'll explore the different things you can do ensure your phone number is completely free of Apple's, shall we say, "influence" on what it can and cannot do. The first scenario is in the case you have already switched to another device, while the second scenario is more elaborate and is targeted towards those of you that are planning to switch.
1. Unregister & STOP
http://supportprofile.apple.com and log-in with your Apple ID. Unregister your iPhone from Apple's system, which will "free" your number of iMessage, Apple ID, and the App Store. Additionally, you will have to reset your Apple ID password and log out from all services.
Done already? The next step is to send a message to 48369 with the word STOP. This should disconnect your number from Apple's iMessage servers for good, and render you able to receive texts from iPhone owners.
2. The "switch" boot-camp for ex-iPhone owners
You still have your iPhone, but want to switch to another device. The first thing to do is to switch off iMessage from the Messages menu in Settings. When you do so, your message bubbles should look green, instead of blue.
iMessage, however, works in the entirety of Apple services, including iCloud, Game Center, iTunes, and the like. If you are using iCloud, it might be a good idea to sign in and remove your number from the Account Details page.
The after-switching period may or may not involve pestering your iPhone-using friends to do the following:
- Deleting and re-adding your phone number as a non-iMessage contact after you switch. This is something Apple recommends for everyone looking to switch.
- Hitting the information icon next to a message they suspect didn't come through to your phone, and re-sending it as a text message.
Additionally, it is said that the iMessage problem often "solves itself" in 45 days, after Apple's servers get full of the unreceived messages sent to your number and basically get the hint that you are out of the system.
Hopefully, this round-up will help solve the messaging woes of iPhone converts.
References: "How To Make Sure You Still Get Texts If You Ditch Your iPhone" - Business Insider