Technology's supposed to make our lives easier. I think by now, most people will have noticed that while tech is good, it's not flawless. A case in point: the junk mail folder.
As spam detection technology has improved over the years, most people have seen a noticeable decline in the amount of junk mail that hits their inbox. Spammers know this and they do their best to get around spam filters. It's a bit of an arms race, and it's not victimless. Myriad legitimate emails still get filtered every day because the technology in use varies from recipient to recipient. Between mail server filters and then one's own computer's email filters, there are myriad ways for messages to get sucked into the vortex of the junk email folder.
I bet most people don't check their junk message folders often. Certainly not daily. I currently have 322 messages in my junk mail folder. While most of them are definitely junk, there were 30+ messages that were legitimate, including one with an invoice attached. (Sorry Jennifer - payment is forthcoming!) Some messages were from a regional Chamber of Commerce and a software company I'm a customer of. Others were from community organizations and some administrative type emails auto-generated by WordPress websites I manage. All legitimate, yet all filtered by my local email software (Microsoft Outlook).
As a sender of email, you probably have a reasonable expectation that your email will make it to your intended recipient. After all, you're a legitimate business person with a perfectly valid reason to be contacting someone. Yet Gmail doesn't know that. Neither does Yahoo, Microsoft, or the thousands of other email providers out there. What they see is only on a technical level, and sometimes those systems flag legitimate messages. These are referred to as "false positives".
Mail server filtering can mean your message never even makes it to the desktop of your intended recipient. They'll never know they missed something from you, unless you get in touch with them in some other way to ask. It seems silly to have to do that, but if you don't hear back from someone regarding an email you sent, it's a reasonable thing to do. Don't assume they're just ignoring you. They might not even know you're trying to reach them.
Of course, it's possible for messages to be diverted to a person's junk folder as well, which means they'll probably not see it for days at best unless they're one of those rare people who checks regularly. Unfortunately, I think it will always be necessary to have a look in the junk mail folder on a daily basis to make sure our technology didn't flag something as a false positive. Here's a positive thought though. When you find a false positive, you can train your email software to not treat future mailings from that sender as junk. You can create a rule to filter the message into a specific folder, or if your email software has a junk mail setting, you can tell it to always trust messages from that sender.
When you do this, you're essentially creating a "whitelist" of trusted email addresses or domains that you want to receive email messages from. If junk messages make it to your inbox, you can also flag them as spam, creating a "blacklist" of email addresses and domains to filter out or delete. You can also talk to your IT department to do the same with the mail server filters so legitimate messages from customers don't get blocked.
In short, I don't think technology is yet at the point where we can completely trust it to never filter a legitimate email message into the junk folder. As my supplier will note, her email and invoice to me hasn't yet been paid, so being blocked can be costly. There's also a potential cost to customer relationships when email transmissions aren't flowing smoothly. Most of the spam is spam, but there could be gold in your junk folder so it pays to check it regularly.