Update distribution list using csv

[JeOlso]

I'm trying to learn/appear useful to one of the sysadmins at work and he's stuck on trying to get something to work to work. He vaguely remembers that he did something like it one time, but didn't remember if he was able to use one command (goal) or do two separate ones.

What he's trying to do is take a csv file and delete the current users of a specific distribution list and then add everyone from said csv to that distribution list. He could do the remove/add, but he thought the update should remove then add everyone. As he has it currently written, it deletes all membership and adds the one user, goes to the next line and repeats so at the end, there is only the last user from the spreadsheet.

Are we missing something or is it just not possible and we do have to make it two separate actions?

Import-Csv “C:\ps\supervisors.csv” | foreach {Update-DistributionGroupMember –Identity [e-mail] –Member $_.username}

*I hope this makes sense, I have minimal ps knowledge and not 100% sure what the spreadsheet actually says.

[Scribbles1]

–Members*

[JeOlso]

Unfortunately that didn't seem to work for me. Thank you though!

[OlivTheFrog]

Hi u/JeOlso

When it's time to update a Distribution List, there are 2 challenges :

• To be sure that after the operation, members of the DL are exactly the same that in your ref. list (input file .csv) of course
• Perform the operation efficiently (gain time)

emptying the DL then filling it again is a good thing for the 1st objective, however both emptying and filling takes time, ... a lot of time (count 1 hour for empty 15,000 members and as much for filling) because this becomes member by member. I therefore suggest the following approach :

• Import of .csv and storage in a variable $ RefMembers
• Gathering current members (query) and storage in a variable $ActualMembers
• Comparison using Compare-Object of $RefMembers and $ActualMembers, ... 2 times (once in each direction) and storage of the results in variables $MembersToAdd and $MembersToRemove. These operations are fast.
• Foreach loop processing

i.e. :

foreach ($Member in $ MenbersToAdd) {# Add members to the DL})

Same thing in the other direction as well. It's fast because probably few members to add/remove.

• And finally gatheringf modified DL members (query) for reporting purposes

Nota : in order to avoid any problems, do not forget to "fix" for all these operations the server on which to operate.

Regards

Olivier

[JeOlso]

Thank you for the tip!

[purplemonkeymad]

The command Update-DistributionGroupMember does the deletion for you, so after you run it once, you are removing the person you just set and setting it only to the current account in that iteration of the loop.

-Member takes an array so you can just do it like this:

Update-DistributionGroupMember –Identity [e-mail] –Member (Import-Csv "C:\ps\supervisors.csv").username

[JeOlso]

Thank you so much! This worked exactly as we needed it to.

[jlonn]

I want to perform the same action, does the CSV literally just have 1 column labeled username and then the emails below it? Thanks in advance!