Receive data from Software Serial

Hi. I've trying to send messages between two Arduino Mega.

What I'm facing now is the received messages will all printed in the same line without spacing.
Any help will be appreciated. Thank you and sorry for my poor description.

you'll need a way to know when a message is completed - like an end marker. that's when you'll go to next line.

I would suggest to study Serial Input Basics to handle this

you need to recognize a termination character when receiving a message, count characters or simply wait some period of time without receiving a character and only send a linefeed at the end of a message

I have recently come to the conclusion that I2C is a more convenient way to communicate between two Arduinos. Have a look at this I2C Tutorial