log4j-core/src/main/java/org/apache/logging/log4j/core/net/SmtpManager.java
log4j-jakarta-smtp/src/main/java/org/apache/logging/log4j/smtp/SmtpManager.java

log4j-core/src/main/java/org/apache/logging/log4j/core/net/MimeMessageBuilder.java
log4j-jakarta-smtp/src/main/java/org/apache/logging/log4j/smtp/MimeMessageBuilder.java