r - sendmailR 与 sendmail 服务器？

Question

我在 Docker 容器中运行 rstudio 服务器，hadleyverse，运行在 Ubuntu 之上，我希望能够从那里发送电子邮件。我尝试遵循本教程并编写了以下代码：

#Load library
library(sendmailR)

#Set mail options (i.e., port number)
sendmail_options(smtpPort=25)

#Send notification and results
sendmail(from="R notification", 
         to="MY@EMAIL.COM", 
         msg="test", 
         subject="R script has finished")

但我收到以下错误

Error in socketConnection(host = server, port = port, blocking = TRUE) : 
  cannot open the connection
In addition: Warning message:
In socketConnection(host = server, port = port, blocking = TRUE) :
  localhost:25 cannot be opened

谢谢您的帮助！