jodd-mail/src/main/java/jodd/mail/EmailAttachmentBuilder.java
protected EmailAttachmentBuilder setContentIdFromNameIfMissing() {
		if (contentId == null) {
			if (name != null) {
				contentId(FileNameUtil.getName(name));
			} else {
				contentId(NO_NAME);
			}
		}
		return this;
	}
protected EmailAttachmentBuilder setContentIdFromNameIfMissing() {
		if (contentId == null) {
			if (name != null) {
				contentId(FileNameUtil.getName(name));
			} else {
				contentId(NO_NAME);
			}
		}
		return this;
	}
Set content ID if it is missing.

@return this
@see #contentId(String)