If you're adding more than a handful of people, it will save you time to drop them into an Excel spreadsheet and import them in one fell swoop.
You can delete someone from a single group or from every group.
Note: Keep in mind that deleting contacts from within a group and removing an entire group (from the main Audience page) are two different actions. Removing a group is like removing a basket that holds those contacts. If the contacts in the group you remove don't exist in any other groups, they will be in Limbo, meaning they're not in any groups and will not be represented in the list of groups. You can view your entire audience (including limbo contacts) by selecting View all contacts from the Audience page.
People are typically moved into Error status for either an invalid email address format or due to delivery issues. In some cases, it won’t be an email address at all -- It could be the header rows from your imported spreadsheets. People are listed on the Opt-out tab after they've opted out of your mailings or after you've manually marked them as an opt-out.
Here's what we suggest about deleting errors and opt-outs:
There are a few reasons to keep these entries around. Email addresses listed on the Error or Opt-out tab are typically there for a reason. Emma will never send to those addresses, and you're not being charged for them, so keeping them on file isn’t doing any harm.
Second, when you delete a record, you are deleting its history as well, so if you need to look it up in the future, it won’t be available unless you undelete it from the Deleted items folder. There may be times when someone contacts you to ask why they haven’t received your emails, and if they had been listed as in Error or Opt-out but were deleted, you'll have to search for them.
Also, if a person has been deleted and tries to sign up for your newsletter again, they will get a message requesting that they reach out to the account owner to be re-added to your account. Had they not been deleted, this process would go through seamlessly.
Is it required to keep these addresses in your account? Not at all. But we tend to think it's easier to keep them around.