iMessage group chat post Android switch

Basically there's not a lot you can do when it involves the pissing match between Google and Apple. Text messaging in general has devolved into a mess with different protocols that isolate one platform from the other. Apple's iMessage service relies upon its iMessage protocol, protected by strict licensing that does not allow any other platform nor third-party app to legally include support for iMessage. Google is attempting to make its RCS protocol the standard for all Android devices, with mixed results -- not every carrier nor every Android texting app includes RCS support, and even though RCS is (for now) open and free to adopt, it's still a proprietary standard and Apple continues to refuse to include any RCS support into its iMessage app so that alone is a major limitation to cross-platform exchanges.

Currently, we're all dependent on SMS and MMS as the only two protocols all text messaging services still support. But both SMS and MMS are very, very dated protocols with origins going back to the 70's. They're Open Source but simply too dated to be upgraded as is to support today's tech needs -- i.e. when it involves iMessge to iMessage users or RCS to RCS users than file size transfers are quite generous, but once an exchange of text messages involve say an iMessage user to a typical Android user, file sizes are much, much more limited (1MB or less). When it involves just text, even SMS is much more limited in its character count than RCS. There's also an over-riding issue that involves different carrier to carrier text message exchanges between platforms where some set arbitrary file size limitations so they automatically scale-down higher res photo or video attachments to reduce file size transfers. (Note this isn't an issue when it's iMessage to iMessage nor RCS to RCS even between carriers as with the former text message transfers involve Apple's online servers and with the latter text message transfers via Google's online servers.)

With iMessge group chats, those get translated into MMS for an Android recipient. And that's an issue that has more to do with iMessage users enabling SMS/MMS support in their iMessage apps. Android text messaging apps don't have any kind of 'support iMessage' option because that's just not doable. Again, Apple won't allow other platforms to support iMessage and it won't include other protocols like RCS into its iMessage app. But text messaging has turned into a mess and there's no sign things will get better. But the same proprietary problem exists with the WhatsApp protocol, the Telegram protocol, and the list goes on. If any text messaging app drops SMS/MMS support, that's going to be a major bummer.
I wish we'd all just migrate back to email. There's POP and IMAP, and all the email services support both or one of them.

 

You could try installing a different messaging app that may work better than the messages app.
I use Textra with no issues with my iPhone friends

 

Textra should work fine for SMS/MMS.

If you want something less limited than MMS (which limits the size of media significantly) then I'm afraid they are going to have to use a different app for this group. I do that with various friends and family groups where we have a mix of platforms. Of course it helps that in the UK many providers charge (excessively) for MMS, which has the result that most people here just don't use MMS. And as iPhones will fall back to MMS unless everyone involved is using iMessage, and iPhone users are no keener than anyone else on being charged 40-65p to send a low-quality photo, there's never any serious question of them using it unless they know that nobody in the group will ever use anything other than an iPhone .