MX (Mail Exchanger) records in DNS are critical for email routing and delivery. Misconfigurations in MX records can lead to email delivery failures, increased vulnerability to email spoofing, and inefficient mail routing. The following areas are key concerns in MX record configuration:

1. **Record Format**: MX records must adhere to the standard format of 'priority fully-qualified-hostname.domain.tld'. Incorrect formatting can lead to misinterpretation by email servers and DNS resolvers. Priority values should be valid integers, and hostnames must be properly formatted.

2. **Priority Values**: MX record priorities should be within the valid range of 0-65535. The lowest value indicates the most preferred mail server. Improperly configured priorities can lead to inefficient email routing.

3. **Duplicate Records**: Duplicate MX records should be avoided. They can cause confusion in DNS resolution, and may lead to unnecessary processing by mail servers. It's important to regularly audit MX records to ensure no duplicates exist.

4. **Hostname Validity**: The hostnames specified in MX records must be valid and resolvable to IP addresses. Non-existent or unreachable hostnames can cause email delivery failures. It's crucial to ensure that these hostnames point to active mail servers through A or AAAA record lookups.

5. **Consistency with SPF Records**: MX record hostnames should be included in the domain's SPF (Sender Policy Framework) record. Inconsistency between MX and SPF records can increase vulnerability to email spoofing and negatively impact email deliverability.

These misconfigurations can result in delayed or failed email delivery, increased susceptibility to email-based attacks, and overall degradation of an organization's email infrastructure reliability. The impact can range from minor inconveniences to severe disruptions in business communication.