Its true the mass invite option DOES NOT work. You have to add your emails one by one but no worries. Hear is an imacro script i created that works using a .csv spread sheet as the data source. it is looped in a way so that it will began at the first email on the spreadsheet once it is submitted it will move to the next email address and so on until the file is complete.
SET !DATASOURCE
Your email list.csv
SET !DATASOURCE_COLUMNS 1
SET !LOOP 2
SET !DATASOURCE_LINE {{!LOOP}}
VERSION BUILD=8300326 RECORDER=FX
TAB T=1
URL GOTO=
type url for facebook HERE
WAIT SECONDS=2
TAG POS=2 TYPE=DIV ATTR=TXT:
Enter you group here use <SP>
for spaces
TAG POS=1 TYPE=A ATTR=TXT:Invite<SP>by<SP>Email
TAG POS=1 TYPE=INPUT:TEXT FORM=ACTION:/ajax/groups/members/add_post.php?source=dialog_typeahead&group_id=482580495149052&refresh=1 ATTR=ID:groupMembersInput CONTENT={{!COL1}}
TAG POS=1 TYPE=BUTTON ATTR=TXT:Invite
WAIT SECONDS=1
1. First things you want to do is make sure your .csv file is located in the "datasources" folder under iMacros. Then in the script above input the name of the file so imacros can find it.
2.Make sure your group is correct in the code. The best way to do it is to record yourself logging into facebook, then the group, click invite by email, paste an email, then click invite. After recording go to edit macros in the imacros window on the left and copy the code.
TAG POS=2 TYPE=DIV ATTR=TXT:
Enter you group here use <SP>
for spaces
TAG POS=1 TYPE=A ATTR=TXT:Invite<SP>by<SP>Email
TAG POS=1 TYPE=INPUT:TEXT FORM=ACTION:/ajax/groups/members/add_post.php?source=dialog_typeahead&group_id=482580495149052&refresh=1 ATTR=ID:groupMembersInput CONTENT={{!COL1}}
TAG POS=1 TYPE=BUTTON ATTR=TXT:Invite
^^^^^^ It will look like this except it will have your group name in there.
3. Now you are ready to run your script. Be sure to have facebook already logged in. Hit "play loop" it should be the last cell on your excel file. If you have 550 emails you will loop 550 times to get all emails.
This is a WORKING script! around 2,000 invites fb will tell you to stop. to get around this you should add this script to the bottom:
SET !EXTRACT NULL
SET !EXTRAC

EST_POPUP NO
URL GOTO= (Graph pad quick calcs) PM me for the actual link sorry im too new
TAG POS=1 TYPE=INPUT:TEXT FORM=NAME:CFForm_1 ATTR=ID:low CONTENT=1
TAG POS=1 TYPE=INPUT:TEXT FORM=NAME:CFForm_1 ATTR=ID:hi CONTENT=10
TAG POS=1 TYPE=INPUT:SUBMIT FORM=NAME:CFForm_1 ATTR=NAME:Random
TAG POS=18 TYPE=TD ATTR=TXT:* EXTRACT=TXT
WAIT SECONDS={{!EXTRACT}}
This randomizes the wait time before it submits a new email. just makes the process appear more human like to fb. You may adjust it accordingly. So where do the invites go? they go directly to that persons email inbox which i found not may people clicked on and joined. But hey at least you know they got it.
Let me know how this works for you all and good luck. Feedback and improving this script would be great also