Using subsearch is not supported for map and you also need max_searches=50 . Try this:
index=YouShoulAlwaysSpecifyAnIndex AND sroucetype=AndSourcetypeToo AND source="UserList.csv" host="prd-p-bjs8j4b5tcmc" sourcetype="SplUsers" "User Lock Status"=0 "User Type"=A
| rename "User Name" AS user_name, "User Master Maintenance_ User Group" AS user_group, "User Lock Status" AS user_lock_status, "Last Logon Date" AS last_logon_date, "First name" AS first_name, "Full Name" AS full_name, "E-Mail Address" AS e-mailAddress
| eval last_logon_date = strptime(last_logon_date, "%m/%d/%Y")
| where (last_logon_date >= relative_time (now(), "-90d")) AND
(last_logon_date <= relative_time (now(), "-60d"))
| eval last_logon_date = strftime (last_logon_date, "%m/%d/%Y")
| sort 0 + last_logon_date
| table user_name,user_group,first_name,full_name,user_lock_status,last_logon_date,e-mailAddress
| map max_searches=99 search="sendemail to = $e-mailAddress$ cc=\"xyz@yahoo.com\" subject=\"User $user_name$ to be locked\"
message="Hi $first_name$,
User $user_name$ will be locked as you didn't login to SAP system since 60 days.
Regards,
SAP Admin.\" sendresults=false footer=\"Kindly contact SAP Admin if you don't want to be locked within 2 business days.\""
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