RDCOM Client报错：使用R发送带Excel附件邮件触发80020009异常

你目前尝试通过R语言的RDCOMClient库发送5封各附带独立电子表格的邮件，待发送的表格路径存放于如下向量：

[1] "C:/Users/sxc3gfl/Documents/data-science-team-master/INTERLINE BRANDS.xlsx"       
[2] "C:/Users/sxc3gfl/Documents/data-science-team-master/POLY-AMERICA, LP.xlsx"       
[3] "C:/Users/sxc3gfl/Documents/data-science-team-master/SO TTI POWER EQUIPMENT.xlsx" 
[4] "C:/Users/sxc3gfl/Documents/data-science-team-master/GENERAC SO.xlsx"             
[5] "C:/Users/sxc3gfl/Documents/data-science-team-master/SO TOTER LLC.xlsx"

经确认路径均正确，使用的发件脚本如下：

path_names <- "C:/Users/sxc3gfl/Documents/data-science-team-master/"

attachments <-  c(paste0(path_names, sheet_names28))

for (sheet in sheet_names28) {
  attachments = c(paste0(path_names, sheet))
  OutApp <- COMCreate("Outlook.Application")
  outMail = OutApp$CreateItem(0)
  outMail[["To"]] = paste("user@outlook.com"
                          , sep=";", collapse=NULL)
  outMail[["subject"]] = "Subject"
  outMail[["body"]] = "Hi -
Attached is the spreadsheet 

"
  purrr::map(attachments, ~ outMail[["attachments"]]$Add(.))
  outMail$Send()
}

前两个表格对应的邮件均可正常发送，运行到第三个路径C:/Users/sxc3gfl/Documents/data-science-team-master/SO TTI POWER EQUIPMENT.xlsx时触发如下报错：

<checkErrorInfo> 80020009 
No support for InterfaceSupportsErrorInfo
checkErrorInfo -2147352567
Error: Exception occurred.

该报错是RDCOMClient调用Outlook COM接口时的通用运行异常，对应可排查的原因如下：

• 附件读取失败：90%以上的该类报错出在附件读取环节，首先检查第三个Excel文件是否被其他程序占用，比如提前打开了该文件编辑未关闭，Excel会给文件加独占锁，Outlook添加附件时无法读取文件就会抛出该异常，前两个文件未被占用所以发送正常。
• 附件大小超限：检查第三个文件的大小，是否超出了你Outlook账号配置的单封邮件附件大小上限。
• COM资源冲突：原代码在循环内重复创建Outlook.Application实例，前两次创建的实例未正常释放，第三次调用时COM接口资源冲突也会触发该报错。

1. 先关闭所有打开的Excel进程，确认报错对应的文件未被占用，且文件大小符合发件限制。
2. 优化发件代码，全局只创建一次Outlook实例，循环内复用实例，发件后及时释放邮件对象，同时添加文件存在性校验，避免无效接口调用，优化后代码如下：

library(RDCOMClient)
library(purrr)

path_names <- "C:/Users/sxc3gfl/Documents/data-science-team-master/"
# 全局创建一次Outlook实例，避免重复创建资源冲突
OutApp <- COMCreate("Outlook.Application")

for (sheet in sheet_names28) {
  attach_path <- paste0(path_names, sheet)
  # 提前校验文件是否存在可读
  if (!file.exists(attach_path)) {
    warning(paste("文件不存在，跳过：", attach_path))
    next
  }
  # 创建邮件项
  outMail <- OutApp$CreateItem(0)
  outMail[["To"]] = "user@outlook.com"
  outMail[["subject"]] = "Subject"
  outMail[["body"]] = "Hi -
Attached is the spreadsheet 

"
  # 添加附件
  outMail[["attachments"]]$Add(attach_path)
  # 发件
  outMail$Send()
  # 释放当前邮件对象
  rm(outMail)
  gc()
  # 可选：加1秒延时，避免频繁调用接口触发限制
  Sys.sleep(1)
}

# 全部发完后释放Outlook实例
rm(OutApp)
gc()

内容的提问来源于stack exchange，提问作者Jaskeil