As reported in a forum thread in Spanish, two language strings are not displayed in the forum language (Spanish), but are instead shown in English when a user tries to report some forum content (in moodle.org) as SPAM.
I can confirm that both stings are translated in AMOS for at least Moodle branches 3.0 to 3.4.
Thanks for pointing out the untranslated strings. We're actually using a customised version of the spam deletion block here on moodle.org, so the only way to add translations of strings is via Language customisation in the Site administration.
I've just copied and pasted strings from AMOS es_mx block_spam_deletion version 2.7 to moodle.org for es and es_mx, so they should appear translated for you now. If you notice any other untranslated strings, or wish to change any translation, please just message me.