Body: <p>It seems rational to me to assume that if a mailing is set up where a group (or past mailing) is excluded, then any records that share the same email address as an excluded record, should also be excluded.</p>
  
  <p>Indeed, to my mind this is totally aligned with the principle behind the "Dedupe by email" option in CiviMail, that stops multiple copies of an email going to the same address, where multiple records share that address.</p>
  
  <p>However in practice this appears not to be the case, which I found out to my disappointment: a mailing was sent to a group (group A) in error, when it should have gone to a different group (group B). As soon as we spotted the error we sent out an apology message as the mailing was leading to some confusion amongst recipients. However, as we were aware that some contacts were in both group A and group B, we decided to send the apology message to group A, but excluded group B from the mailing, because for those people the mailing was not erroneous. Unbeknown to us at that time there were a handful of additional contact records in group A that shared the email address of records in group B. The result was that although we assumed that no email address in group B would be sent the apology, in fact a small number did get the apology leading to further confusion.</p>
  
  <p>What's the opinion of others on this? I understand that things can get tricky when trying to handle the nuances of scenarios where multiple records share the same email address, but in this situation where we were deliberately excluding a set of addresses, it does seem sensible to ensure that those addresses get removed from the mailing, even where that involves records that share the address.</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-05T19:14:41.990Z
Comments.Text: If John and Maria are both in your DB but use the same email address. And let's say that John has opted out but Maria hasn't, or Maria should get an email for some reason but John is in a group that should not and hence is excluded, how would you see that working?
Comments.UserDisplayName: petednz - fuzion
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-05T19:47:18.070Z
Comments.Text: I think that you are sending messages to contacts and the selection is based on whethertehy are in the group and then getting the emails to use. So at selection it won't know that the emails are the same. If it weren't an apology message, then this would be correct behaviour. Sharing emails is always problematic.Given that (hopefully) mistakes are infrequent, I wouldn't want a special case to override normal behaviour.
Comments.UserDisplayName: Mick Kahn
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-06T09:19:46.113Z
Comments.Text: https://civicrm.stackexchange.com/questions/27612/can-multiple-mailings-have-deduplicated-email-addresses-so-each-address-will-no is obviously relevant.
Comments.UserDisplayName: Mick Kahn
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-06T13:36:21.293Z
Comments.Text: @petednz-fuzion I agree that it's not a straightforward issue, and that there are use cases when it is desirable not to exclude all excluded addresses, but rather to exclude only excluded contacts. In which case what's needed is a user-facing option to toggle between the two approaches.
Comments.UserDisplayName: Graham
Tags: <civimail><duplicate-contacts>
Title: If I exclude an address from a bulk email is it rational to assume that the mailing won't go to that address?
ThreadText: # If I exclude an address from a bulk email is it rational to assume that the mailing won't go to that address?
  
  (Asked by: username_0 on 2019-05-05)
  
  It seems rational to me to assume that if a mailing is set up where a group (or past mailing) is excluded, then any records that share the same email address as an excluded record, should also be excluded.
  
  Indeed, to my mind this is totally aligned with the principle behind the "Dedupe by email" option in CiviMail, that stops multiple copies of an email going to the same address, where multiple records share that address.
  
  However in practice this appears not to be the case, which I found out to my disappointment: a mailing was sent to a group (group A) in error, when it should have gone to a different group (group B). As soon as we spotted the error we sent out an apology message as the mailing was leading to some confusion amongst recipients. However, as we were aware that some contacts were in both group A and group B, we decided to send the apology message to group A, but excluded group B from the mailing, because for those people the mailing was not erroneous. Unbeknown to us at that time there were a handful of additional contact records in group A that shared the email address of records in group B. The result was that although we assumed that no email address in group B would be sent the apology, in fact a small number did get the apology leading to further confusion.
  
  What's the opinion of others on this? I understand that things can get tricky when trying to handle the nuances of scenarios where multiple records share the same email address, but in this situation where we were deliberately excluding a set of addresses, it does seem sensible to ensure that those addresses get removed from the mailing, even where that involves records that share the address.
  
  **Tags:** civimail, duplicate-contacts
  
  > **Comments:**
  > **username_1**: If John and Maria are both in your DB but use the same email address. And let's say that John has opted out but Maria hasn't, or Maria should get an email for some reason but John is in a group that should not and hence is excluded, how would you see that working?  
  > **username_2**: I think that you are sending messages to contacts and the selection is based on whethertehy are in the group and then getting the emails to use. So at selection it won't know that the emails are the same. If it weren't an apology message, then this would be correct behaviour. Sharing emails is always problematic.Given that (hopefully) mistakes are infrequent, I wouldn't want a special case to override normal behaviour.  
  > **username_2**: https://civicrm.stackexchange.com/questions/27612/can-multiple-mailings-have-deduplicated-email-addresses-so-each-address-will-no is obviously relevant.  
  > **username_0**: @username_1 I agree that it's not a straightforward issue, and that there are use cases when it is desirable not to exclude all excluded addresses, but rather to exclude only excluded contacts. In which case what's needed is a user-facing option to toggle between the two approaches.  
  
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  ## 0 answers
  
  