An email address can look right but still be wrong. Real email uses in depths address validation to check if emails really exist without sending any messages.
From the Real Email dashboard you can upload a csv file to interactively validate any email address in it. This can be used to filter email group lists or mail out lists.
Many programs allow for importing and exporting csv files, including form spreadsheets and email sending platforms like MailChimp and SendInBlue. For more control you may like to process the files using the api and shell scripts.
If you would like more control you can validate a csv file using your Real Email api key and the bellow bash shell script. First login to http://isitarealemail.com and get your API key and place it into the Authorization header.
Given an example file like emails-input.csv
If you run that through the bellow script.
#!/bin/bashwhile IFS='' read -r line || [[ -n "$line" ]]; doecho $line, `curl "https://isitarealemail.com/api/email/validate?email=$line" -H 'Authorization: bearer xxx' | jq .status`;done < emails-input.csv > emails-output.csv
Then It will give you the output file that looks like this.