Is the Social Engineering Spearphishing Attack Outdated?

Hi everyone,

Today I attempted OTW's spearphising tutorial as seen here. To summarise I chose to send an email via my gmail account to another gmail account of mine. I chose the fileformat option, meterpreter payload, the Microsoft word RTF MS087-10 exploit, but I got an error message the following:

! Unable to deliver email. Printing exceptions message below, this is most likely due to an illegal attachment. If using GMAIL they inspect PDFs and is most likely getting caught.

Press {return} to view error message.

(552, '5.7.0 This message was blocked because its content presents a potential\n5.7.0 security issue. Please visit\n5.7.0 https://support.google.com/mail/answer/6590 to review our message\n5.7.0 content and attachment content guidelines. xt1sm9097446wjb.32 - gsmtp')

* SET has finished delivering the emails

I read more guides and they actually recommend the word exploit because its harder to detect. What should I try next? Is there a more useful method now?