SPAM is over the top

[vihosting]

We all hate spam - that's nothing new. What is new is the increased spam that the majority of my hosting clients are experiencing. But there is a twist this time - legitimate messages that they are sending out are being marked as spam at the recipients end (making them feel unprofessional and messages getting missed) as well as legitimate emails coming in being marked in the same fashion.

Add to that, many incoming emails are being marked as spam because there is a spam in the message, with the legitimate email sent as an attachment. What is up with that???

And finally, many people that I (and my clients) been able to email in the past are no longer to receive emails because their server is rejecting them and bouncing them back.

Is the mail server that Host Nexus uses marked in cyber world and no longer able to effectively handle business mail?

I'm about to loose my mind with the calls I'm getting from clients who are so fed up with this spam issue. I have been in touch with tech support so much and continually am told that there is no problem when I can often pinpoint the day that a change has occurred (both for me and an influx of calls from clients). Their suggestion is to use the spam filtering tool from the plesk control panel but that is not an option that any of my clients want to undertake themselves and I don't feel that they should have to.

I've considered moving them all over to gmail accounts but I did this for my own business and ran into other problems in the process.

Once and for all, can someone in the "know" tell me how to effectively control spam on my client's behalf since Tech Support is unable to help.