Messaging app have RCS?

Nope, only Google Messages and certain carrier apps support RCS. Google has not exposed a public API for it yet.

pinetree_raccoon To the best of my knowledge the AOSP Messages app included in GrapheneOS does NOT support RCS functionality. You would have to download and use the Google Messages app. I haven't tried it myself yet but will need to since I have shit for cell service and can't afford to miss messages.

mylesofsmiles Does your service provider not offer wifi calling? If so, SMS will be delivered over wifi.
From what I understand of RCS, it routes every message through google. And further, in order for RCS to be used, BOTH ENDS have to support it. If the person sending the message doesn't support RCS, then it will be delivered using SMS anyway.

abcZ I am on T-Mobile (US) and they do offer Wi-Fi calling. All I know is in the past I would miss text messages out of cellular range on AOSP messages on LineageOS and it was a problem. Once I loaded Google Messages and enabled Chat Features on it everything worked fine. I loathe the idea of using Google Messages but it just works so well and since most of my contacts are on Android having the ability to send full resolution pictures is almost a necessary evil.

mylesofsmiles SMS should still be delivered once you get your connection back. Seems strange if you completely miss them. I'd also suggest giving QKSMS a try, its a real nice and open source SMS/MMS application.

But yes, I do understand the picture resolution issue. Not a major issue for me though, I've talked everyone I want to share data with to use a private instance of Nextcloud that I have running.

abcZ Yeah, I did end up receiving them once back in range of cellular service. I would miss time sensitive messages though and it wasn't good for business. I will look into QKSMS, thanks for the suggestion! I would prefer not to use Google Messages but it is hard not to when seemingly everyone around me uses it.

So I noticed with QKSMS the app hasn't been updated in a year and it appears to be buggy. How does everyone here feel about Textra? I know it isn't FOSS but it looks like a more reliable version of QKSMS that is regularly updated.

If you don't have network connection, it doesn't matter what protocol the message was sent with, it still won't be delivered until you have network again. Your network options include precisely; cellular and wifi. SMS will deliver over wifi-calling. So you won't miss messages on SMS that you wouldn't miss also with RCS.