typo fix

Author: Ruchika-mittal01

defender-office-365/tenant-allow-block-list-email-spoof-configure.md

@@ -47,7 +47,7 @@ This article describes how admins can manage entries for email senders in the Mi
 
 - For blocking inbound and outbound email from a domain, any subdomains in that domain, and any email addresses in that domain, create the block entry using the syntax: `*.TLD`, where `TLD` can be any top-level domain, internal domain, or email address domain.
 
-- For blocking inbound and outbound email from a sudomain in a domain and any email addresses in that subdomain, create the block entry using the syntax: `*.SD1.TLD`, `*.SD2.SD1.TLD`, `*.SD3.SD2.SD1.TLD`, etc. for internal domains and email address domains.
+- For blocking inbound and outbound email from a subdomain in a domain and any email addresses in that subdomain, create the block entry using the syntax: `*.SD1.TLD`, `*.SD2.SD1.TLD`, `*.SD3.SD2.SD1.TLD`, etc. for internal domains and email address domains.
 
 - For details about the syntax for spoofed sender entries, see the [Domain pair syntax for spoofed sender entries](#domain-pair-syntax-for-spoofed-sender-entries) section later in this article.