N4thaniel

Import users from a csv files and send a custom message using specific shortcodes.
You can choose capabilities for new users.
(original import csv script from AndyDunn)

CSV User Import with custom email message

Allows you to import a list and create users from a CSV files . Allows you to send a custom email with credentials

DCoda

This plugin is only supported on PHP 5.2 or greater.
 
ExportReaders easily allows you to export your users details for use elsewhere. 
Just select the roles you with to export and set the criteria to select the commenters and download its that simple. 

If you are having trouble and cannot find the answers in the <a href="http://exportreaders.dcoda.co.uk/help/faq/" rel="nofollow ugc">FAQ</a> you can post your support questions to the <a href="https://wordpress.org/tags/export-readers" rel="ugc">WordPress Support Forum</a>
If you find ExportReaders useful please rate it at <a href="https://wordpress.org/extend/plugins/export-readers/" rel="ugc">wordpress.org</a> and please consider making a <a href="http://exportreaders.dcoda.co.uk/donate/" rel="nofollow ugc">donation</a> to help us set aside more hours to maintain ExportReaders
ExportReaders is written by <a href='http://dcoda.co.uk' rel="nofollow ugc">dcoda</a>
You can check out our other plugins <a href="https://profiles.wordpress.org/users/dcoda/" rel="nofollow ugc">here</a>
If you require a custom plugin you can contact us <a href="http://dcoda.co.uk/contact/" rel="nofollow ugc">here</a> and maybe we could write it for you.
<h3>Copyright</h3>
(c) Copyright DCoda Limited, 2007 -, All Rights Reserved.
This code is released under the GPL license version 2, available here:
<a href="http://www.gnu.org/licenses/gpl.txt" rel="nofollow ugc">http://www.gnu.org/licenses/gpl.txt</a>
There are so many possibly configurations of installation the plugin can be installed on we limit testing to a PHP 5.2+ Linux platform running the latest version of WordPress at the time of release but it is released WITHOUT ANY WARRANTY; 
 without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

ExportReaders

Selectively export all your reader details ( users and commenters )

CSV User Import with custom email message vs ExportReaders