"I am getting too much spam"
Sadly a problem all mail providers battle daily. Here are a couple things that you can try to get your mail spam under control.
1. In settings on your mailbox, click the "spam" tab. Level should be set to "very high". Make sure to watch your spam folder as you are likely to send some good email there.
2. If it is already set to very high, then login as user and look at the spam in your mailbox. Is the "spam" regular advertising with unsubscribe links that looks like maybe you signed up for? Then that is "ham" or "gray" email which they may have accidentally signed up for at some point. I advise you use unsubscribe links where possible and add to blacklist using the root domain of the sender - instead of email@example.com blacklist *macys.com - realizing you will send not see anything from the macys.com domain. Be careful - blocking mail providers like gmail.com hotmail.com or yahoo.com will outright reject emails from them, not send them to spam.. Don't do that...
3. Check who the mails are being sent to by expanding the headers (down arrow in the upper right of mail window). If you see a lot of firstname.lastname@example.org then go to Settings and add a filter to send anything sent to mailcity.com to the spam folder. Do this by going to settings->filters then in the filters list, click + icon at bottom of page. Name filter: Spam Mailcity match all following rules - To contains mailcity.com execute the following actions move message to spam. Then save. Now watch your spam folder for good emails that may get caught, and ask user to update address book and send to lycos.com email address.
4. If you have a huge blacklist copy it and paste into excel, then do "text to columns" using @ as delimiter. Remove the mailbox, and then check the list of domains for known email providers like gmail, hotmail, etc. Then I add * at the beginning and replace their blacklist - this will block repeat spammers who use different mailboxes to send on the same domain. Again, be VERY CAREFUL doing this.