Small formatting and doc tweaks

FAQ.md

@@ -62,9 +62,10 @@ This module, however, directly talks to the *recipient's* server for
 *incoming* emails, so neither your credentials nor the switch to port
 465 or 587 is of any use here.
 
-If your internet connection is within a dynamic range (often the case
-for private use) or it doesn't have a proper reverse DNS entry, the
-servers for many email domains will reject connections from you. This
-can *not* be solved by using your provider's mail server. Instead, you
-have to use the library on a machine with an internet connection with
-static IP address and a proper reverse DNS entry.
+If your internet connection is within an IP pool (often the case for
+private use) or it doesn't have a proper reverse DNS entry, the servers
+for many email domains (depending on their configuration) will reject
+connections from you. This can *not* be solved by using your provider's
+mail server. Instead, you have to use the library on a machine with an
+internet connection with static IP address and a proper reverse DNS
+entry.

validate_email/smtp_check.py

@@ -175,10 +175,10 @@ class _SMTPChecker(SMTP):
 
 
 def smtp_check(
-        email_address: EmailAddress, mx_records: List[str],
-        timeout: float = 10, helo_host: Optional[str] = None,
-        from_address: Optional[EmailAddress] = None, debug: bool = False
-        ) -> bool:
+    email_address: EmailAddress, mx_records: List[str], timeout: float = 10,
+    helo_host: Optional[str] = None,
+    from_address: Optional[EmailAddress] = None, debug: bool = False
+) -> bool:
     """
     Returns `True` as soon as the any of the given server accepts the
     recipient address.

validate_email/validate_email.py

@@ -27,12 +27,12 @@ simply accept everything and send a bounce notification later. Hence, a
 
 
 def validate_email_or_fail(
-        email_address: str, *, check_format: bool = True,
-        check_blacklist: bool = True, check_dns: bool = True,
-        dns_timeout: float = 10, check_smtp: bool = True,
-        smtp_timeout: float = 10, smtp_helo_host: Optional[str] = None,
-        smtp_from_address: Optional[str] = None, smtp_debug: bool = False
-        ) -> Optional[bool]:
+    email_address: str, *, check_format: bool = True,
+    check_blacklist: bool = True, check_dns: bool = True,
+    dns_timeout: float = 10, check_smtp: bool = True,
+    smtp_timeout: float = 10, smtp_helo_host: Optional[str] = None,
+    smtp_from_address: Optional[str] = None, smtp_debug: bool = False
+) -> Optional[bool]:
     """
     Return `True` if the email address validation is successful, `None`
     if the validation result is ambigious, and raise an exception if the
@@ -43,7 +43,7 @@ def validate_email_or_fail(
         regex_check(email_address=email_address)
     if check_blacklist:
         domainlist_check(email_address=email_address)
-    if not (check_dns or check_smtp):  # check_smtp implies check_dns.
+    if not check_dns and not check_smtp:  # check_smtp implies check_dns.
         return True
     mx_records = dns_check(email_address=email_address, timeout=dns_timeout)
     if not check_smtp: