I'm fine with missing things if people don't feel like using any of the methods I have to get in touch with me. However, instead of either not bothering or using one of the communication channels we have in common, people tend to ask my partner to relay messages to me. So short of starting to use Whatsapp (which I'd really rather not do, and which requires installing a different OS on my phone - and possibly get a data subscription as well), the burden is on my partner to either tell them to contact me directly, or to relay the messages.
Any good tips for others ways of dealing with this are very welcome.