Title: duplicate subscriptions being allowed
Last modified: August 30, 2016

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# duplicate subscriptions being allowed

 *  [Stephen S](https://wordpress.org/support/users/ssuess/)
 * (@ssuess)
 * [11 years ago](https://wordpress.org/support/topic/duplicate-subscriptions-being-allowed/)
 * The plugin will allow someone with the same email to subscribe twice if they 
   simply use a capital letter (ie both [someone@somewhere.com](https://wordpress.org/support/topic/duplicate-subscriptions-being-allowed/someone@somewhere.com?output_format=md)
   and [Someone@somewhere.com](https://wordpress.org/support/topic/duplicate-subscriptions-being-allowed/Someone@somewhere.com?output_format=md)
   can be subscribed at the same time). This results in duplicate emails being sent
   to these users. The plugin should prevent an existing email (no matter capitals
   or lowercase) to only be subscribed once.
 * [https://wordpress.org/plugins/subscribe2/](https://wordpress.org/plugins/subscribe2/)

Viewing 4 replies - 1 through 4 (of 4 total)

 *  [Matt Robinson](https://wordpress.org/support/users/mattyrob/)
 * (@mattyrob)
 * [11 years ago](https://wordpress.org/support/topic/duplicate-subscriptions-being-allowed/#post-6191670)
 * [@ssuess](https://wordpress.org/support/users/ssuess/) / Stephen
 * Subscribe2 works in a way that is compliant with internet email standards:
    [http://www.ietf.org/rfc/rfc5321.txt](http://www.ietf.org/rfc/rfc5321.txt)
 * In fact the 2 emails addresses you listed above should probably be considered
   distinct and separate email addresses. by ‘fixing’ this issue and classing them
   as the same this could well cause issues on some sites and servers that obey 
   the standards more rigidly than your server seems to.
 *  Thread Starter [Stephen S](https://wordpress.org/support/users/ssuess/)
 * (@ssuess)
 * [11 years ago](https://wordpress.org/support/topic/duplicate-subscriptions-being-allowed/#post-6191685)
 * Thanks for getting back to me, I appreciate it. You have overall made a really
   fantastic plugin. I will try to write some code on my own that fixes this since
   you don’t see it as a bug. But I honestly have NEVER seen a case where this was
   supported by ANY major email provider, I would love to see an example if you 
   have one. Try to sign up at gmail, or yahoo, or icloud or any other service you
   can find on the internet with two identical letter emails but with varying upper
   and lower case – You will find that none of them let you. So whether or not it
   is in the spec, the vast majority of cases in practice do not allow this, and
   I don’t believe the plugin should either. At the very least it should warn the
   user when creating this email that the other one already exists and give them
   the option to cancel.
 *  [Matt Robinson](https://wordpress.org/support/users/mattyrob/)
 * (@mattyrob)
 * [11 years ago](https://wordpress.org/support/topic/duplicate-subscriptions-being-allowed/#post-6191687)
 * [@ssuess](https://wordpress.org/support/users/ssuess/) / Stephen
 * I can understand your point but when agreed and ratified standards (even ones
   that are widely not employed) are ignore we run the risk of then encountering
   other standards that we can choose to ignore and make a mess as back as Internet
   Explorer!
 * That said, it might well be worth considering a filter to allow Subscribe2 to
   sanitize the name part of the email to lower case (as it does for the domain 
   part currently) so individuals such as yourself can code around this if they 
   so desire.
 *  [Jason Hendriks](https://wordpress.org/support/users/jasonhendriks/)
 * (@jasonhendriks)
 * [11 years ago](https://wordpress.org/support/topic/duplicate-subscriptions-being-allowed/#post-6191688)
 * Listen to you quoting RFC5321 😀 I love it!

Viewing 4 replies - 1 through 4 (of 4 total)

The topic ‘duplicate subscriptions being allowed’ is closed to new replies.

 * ![](https://ps.w.org/subscribe2/assets/icon-256x256.png?rev=2318630)
 * [Subscribe2 - Form, Email Subscribers & Newsletters](https://wordpress.org/plugins/subscribe2/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/subscribe2/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/subscribe2/)
 * [Active Topics](https://wordpress.org/support/plugin/subscribe2/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/subscribe2/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/subscribe2/reviews/)

## Tags

 * [duplicate emails](https://wordpress.org/support/topic-tag/duplicate-emails/)

 * 4 replies
 * 3 participants
 * Last reply from: [Jason Hendriks](https://wordpress.org/support/users/jasonhendriks/)
 * Last activity: [11 years ago](https://wordpress.org/support/topic/duplicate-subscriptions-being-allowed/#post-6191688)
 * Status: not resolved