Though our emarketing software support importing recipients from files (txt, csv, xls and xlsx), but we recommend you to prefer the .txt or .csv files. Because importing a plain .txt or .csv file is very fast, .xls(x) is slower due to this needs to connect to the Excel application, and do the data format converting.
Specially, if a file contains thousands recipients, the difference is obvious.
So, if your contacts are stored in the Excel document, please save it as .txt or .csv file first, and then import them to our email and emailing software.
This article is applied to AMS Birthday/Standard Edition, Email Checker Pro.