The first action to take is to review your spam filtering.
A large number of people still have their main spam filter operating on their PC in conjuction with their mail client, eg. Outlook. This is now not usually the best approach. Most Mail Providers (usually your website hosting company) can apply a spam filter and virus check any mail attachments before the mail ever reaches you. Each day you will receive a single email detailing any spam which has been detected and quaranteened. There is usually enough info there for you to assess if it is indeed spam. If you see a mail which has been wrongly classed as spam you can retrieve it into your normal mail box.
In conjuction with the above you should be be able to create ‘White Lists’ and ‘Black Lists’. If the spam system incorrectly traps a ligitimate email you simply enter the senders email address in the ‘White List’ and it will never be treated as spam again. Similarly if you consistantly receive spam from the same sender you can add their email address to the ‘Black List’ which will ensure it is always blocked. Note, seasoned spammers continually change their ’email’ address so this can have limited effect. Your Mail Server Host uses additional advanced techniques to detect spam.
So, log on to your ISP account and go to your email settings. Note that you may not be able to adjust these settings from your web-mail console where you can view/collect your mail. You may have to log on to your general hosting account.
Try unsubscribing if you are given the option. Check the bottom of a spam email and if there is an option to un-susbscribe try it. Although many spam email sources use somewhat questionable means to obtain your email address many of them also realise that if you are not interested you will simply block it so do provide a ligitimate means of unsubscribing. (it is often said that by doing this you are confirming a ligitimate email address but seasoned spammers don’t care about this they will keep bombarding you anyway so always best to try and unsubscribe if you can).
In addition there are a number of steps you can take to minimise spam going forward;
In practice you arrange to have all the mail addresses re-directed to your main email address (but the sender will never know this). Why do this? If spam becocomes a problem on a partivular address you can cancel it without affecting the others. It also lets you know which address has been passed to the spammers. Note – sometimes websites get hacked for the sole purpose of ‘stealing’ the subscriber list so your email address may not have been deliberately passed on