Background job finished but Error sending data

Dear all,

report is running in my prod server . once this report completed sapuser get mail . when i check the job status it shows

Job started

Step 001 started (program GP4CF9U420G825I4P7DU8XY49WH, variant CUSTOMEROUTSTD, user ID S2K_BASIS)

Spool request (number 0000012259) created without immediate output

Error sending data (4)

Job finished

one more clarity i required

this report should goes to 4 SAP users . how can i configure this report to 4 sapusers

kindly suggest me