Can I put affiliate links in my emails?

What the documentation actually bans

One article exists purely to list which links are not allowed in a systeme.io email, and it never mentions affiliate marketing. Its rules are general, aimed at anything that can hurt deliverability.

Nor does any of the three say anything about affiliate links as a category. The word turns up once across all of them, in a line asking you to tell affiliates to keep pre-written sequences consistent. That is about the people, not about their links.

• One landing page per link. "Changing links that redirect to multiple pages depending on the click are prohibited." A link that shows a different offer depending on who clicks, or rotates between several pages, is banned outright.
• The link's domain should match the sending domain. systeme.io calls this "the most optimal format", worded as a recommendation rather than a rule with the same weight as the redirect ban.
• No domain on a blacklist. systeme.io points to outside tools for checking a link or a domain's reputation before using it.
• Shortened links are discouraged. Its stated reason is that the landing page of a link has to be clear from inside the email body, which a shortener hides by design.

A second, more advanced guide points to a stricter version of the same rule, tied to an outside restriction rather than a systeme.io preference. Citing Gmail's own restrictions, it asks users directly not to use link reducers such as Bitly or TinyURL. A third article on how spam filters work calls shortened links "frequently associated with phishing", and separately warns that too many links pointing at different external domains can raise suspicion, "especially if some of those domains have a poor reputation".

Where a typical affiliate link lands against these rules

Affiliate links come in more than one shape, and the rules above do not treat them all the same way.

A rotator or a cloaking link, the kind that sends different clickers to different offers behind one URL, is exactly what the single-landing-page rule bans. So is a link that splits traffic by geography or device behind one address, because that is still one link resolving to more than one page depending on the click.

A shortened tracking link, common on some affiliate networks, sits in the discouraged category rather than the banned one, but two of the three articles single it out on its own, and one ties it directly to a restriction from Gmail rather than a systeme.io house preference.

A single, direct tracking link straight to one vendor's page, the plainest form an affiliate link can take, is not named as a problem by any of the three articles. It does not redirect by click, it is not shortened, and it resolves to one page. Its domain will not match the sending domain, which the documentation calls suboptimal rather than forbidden.

The part that is not written down

No article takes a position on affiliate links as a category. What exists is a set of general rules that several common affiliate-link techniques happen to break, plus a domain-matching preference that almost every affiliate link breaks by definition, since it points at someone else's site. Whether that mismatch alone is enough to cause a problem is not stated either way.

The consequence that is spelled out

systeme.io reserves the right to block the email outright if a link inside it is judged dangerous, in the interest of protecting deliverability for everyone else on the platform. That is described as systeme.io's own judgement call, checked against blacklists and the signals in its content scanning, not a fixed keyword filter on the word affiliate or on any specific link shortener.