Will using a dollar sign in an email subject line cause spam issues?
Summary
What email marketers say11Marketer opinions
Email marketer from Sendinblue explains that using a dollar sign ($) in your subject line can be seen as a 'spam trigger' and hurt your open rates, and recommends testing.
Email marketer from SuperOffice says that using symbols such as the dollar sign may trigger spam filters and negatively impact the performance of the email campaign, and suggests testing.
Email marketer from Reddit user u/EmailExpert responds that using a dollar sign in the subject line is not an immediate trigger but depends on the context and overall email quality. They recommend avoiding excessive use of such symbols.
Email marketer from Email Marketing Forum user ForumUser42 states that a single dollar sign is not a guaranteed spam trigger. He goes on to say it's important to make sure your email practices are good in general.
Email marketer from Litmus recommends focusing on personalization and relevance in subject lines rather than worrying too much about single symbols. Good data practices and segmentation will have a more significant impact.
Email marketer from Mailjet shares that while special characters, including dollar signs, were once a trigger for spam filters, modern filters are more sophisticated. Using them sparingly and naturally is unlikely to cause issues. Overuse, however, can still raise red flags.
Email marketer from Campaign Monitor includes special characters, such as the dollar sign, within a list of words to avoid when writing subject lines, due to the fact these may trigger spam filters.
Marketer from Email Geeks answers that using dollar signs in subject lines is a myth and won't cause deliverability problems, as long as recipients have explicitly asked for the email.
Email marketer from GMass shares that using symbols, including the dollar sign, can sometimes improve open rates if used correctly. But they also advise that the content of the email matters more.
Email marketer from EmailOnAcid shares that while subject lines play a role, a single dollar sign is unlikely to cause issues. The overall reputation of the sender, authentication, and engagement rates are more critical factors for deliverability.
Email marketer from HubSpot advises that while dollar signs aren't always bad, be cautious and test your subject lines to ensure they don't negatively impact deliverability. Focus on providing value and relevance to your audience.
What the experts say4Expert opinions
Expert from Email Geeks simply answers 'No' to the question regarding dollar signs causing issues in subject lines.
Expert from Email Geeks and marketer from Email Geeks discuss the LOTS_OF_MONEY rule in SpamAssassin. Laura mentions the LOTS_OF_MONEY rule has a low score of 0.01, and that if THAT makes your mail be marked as spam, then you have much, much bigger problems. Laura states the rule is more complex than mentions a $ in the subject line and it wholly does not apply to the question that was asked, and Louis agrees it doesn't search the subject at all.
Expert from Word to the Wise, Laura Atkins, explains that focusing on bypassing spam filters is not a sustainable strategy. She focuses on authentication (SPF, DKIM and DMARC) setup, good sending practices, and respecting recipient preferences are essential for reaching the inbox. She makes no direct comment on special characters.
Expert from Spamresource explains that while using a dollar sign may not directly trigger a spam filter, it is a high-risk approach and that it depends heavily on other factors such as IP reputation, authentication, and content. They advise being extremely cautious when considering such tactics.
What the documentation says4Technical articles
Documentation from Google advises that bulk email senders avoid practices that spam filters commonly use to identify unwanted messages. This includes, but is not limited to, the use of special characters and symbols in the subject line.
Documentation from Microsoft Bulk Email Senders Guidelines recommends avoiding excessive use of special characters and symbols in the subject line, including the dollar sign, as it may trigger spam filters. It is also very important to ensure SPF, DKIM and DMARC records are set up correctly.
Documentation from Apache SpamAssassin explains about the LOTS_OF_MONEY rule, which looks for excessive use of monetary symbols and terms within the email body, not specifically the subject line. The rule has a low score meaning it will only contribute to a spam score if other issues are present.
Documentation from RFC 5322 explains that there are no specific restrictions on using the dollar sign ($) or other special characters within the email subject line field from a purely technical perspective. The interpretation of such characters is up to the receiving mail system and its spam filters.