9/10 times for me it's because I'm filtering them out. It's not a good feeling to go back to work after a few days being out to a full inbox.
The other 1/10 of the time is because I probably pushed something out last-minute before I left due to some deadline, and I want to make sure my coworkers have their questions answered. I don't necessarily look at it as a fear of being fired, more so as someone who has been on the opposite end of that scenario and it's frustrating. If spending 30 minutes answering an email from a coworker on my vacation prevents a day's worth of frustration on their end, yeah, I'll take one for the team.
The other 1/10 of the time is because I probably pushed something out last-minute before I left due to some deadline, and I want to make sure my coworkers have their questions answered. I don't necessarily look at it as a fear of being fired, more so as someone who has been on the opposite end of that scenario and it's frustrating. If spending 30 minutes answering an email from a coworker on my vacation prevents a day's worth of frustration on their end, yeah, I'll take one for the team.