[Mailman-Users] Why my Mailman Send monthly reminder of passwd to our users twice

[Muhammad Ashraf]

 I am in trouble because my mailman send a monthly reminder twice to a
 users.this happens on each first day of each month.How i can prevent my
 mailman send reminder only one time at each mouth's first day 
  
 Regards,
 Hope remains forever.
 Ashraf
 AIE