One devious way of attacking people, before the Internet, was to drown them in mail, such as unwanted magazines.
Long ago, people with too much available time would fill out forms in their victims name - and subscribe her / him to assorted unwanted magazines. Nowadays, one might do that with email, to people unwise enough to publicise their account name or email address.
Blogger has similar options that may let us annoy people, also - possibly, inadvertently.
One way to protect yourself, and your blog, from unwittingly being used to annoy people, is to setup FeedBurner email distribution - then redirect the blog feed to the FeedBurner URL.
The first email received will be a verification request.
When somebody's email address is entered, to subscribe to a FeedBurner feed, the first email that a new subscriber gets is a subscription verification request.
Any person, receiving a verification request, and not having intentionally requested a subscription, can ignore the request - and will receive no more email for that feed.
There is a downside to the verification, though. If you do intentionally request a subscription - and fail to respond to the verification request - you won't get any email for that feed, either.
Verify the status of the subscriptions, for the feed.
If your blog uses FeedBurner Email Distribution, and you have unhappy would be readers reporting that they are not getting their anticipated subscription updates, check the FeedBurner Subscription list, using "View Subscriber Details".
Subscribers with a Status of "Unverified", if complaining to you, should search their email Inbox (possibly, "Bulk / Spam"), and look for an unanswered subscription verification request. If the verification request is old enough, they may need to subscribe again - possibly, after you remove the Unverified entry by clicking on the "X" under "Action".
Advise your would be subscribers that they should verify the subscription.
Simply advise your would be subscribers to look for, and answer, the subscription verification request - if they did intentionally subscribe. And apologise to those who did not intentionally subscribe.
And instruct them to check any email filter settings.
And if either you - or your would be subscribers - use non GMail based email, have them check their email filters. Some email - but not all - may be found in the "Bulk" / "Spam" folders. And some may need to check for "bounced" email notices.
An Important Update
If you did not use a Blogger / Google account when you Followed this blog, years ago, you are probably not Following now . During the past...